Liver transplantation in patients with portal vein thrombosis

Guidelines for the management of coagulation disorders in patients with cirrhosis

Coagulation management in the patient with cirrhosis has undergone a significant transformation since the beginning of this century, with the concept of a rebalancing between procoagulant and anticoagulant factors. The paradigm that patients with cirrhosis have a greater bleeding tendency has changed, as a result of this rebalancing. In addition, it has brought to light the presence of complications related to thrombotic events in this group of patients. These guidelines detail aspects related to pathophysiologic mechanisms that intervene in the maintenance of hemostasis in the patient with cirrhosis, the relevance of portal hypertension, mechanical factors for the development of bleeding, modifications in the hepatic synthesis of coagulation factors, and the changes in the reticuloendothelial system in acute hepatic decompensation and acute-on-chronic liver failure. They address new aspects related to the hemorrhagic complications in patients with cirrhosis, considering the risk for bleeding during diagnostic or therapeutic procedures, as well as the usefulness of different tools for diagnosing coagulation and recommendations on the pharmacologic treatment and blood-product transfusion in the context of hemorrhage. These guidelines also update the knowledge regarding hypercoagulability in the patient with cirrhosis, as well as the efficacy and safety of treatment with the different anticoagulation regimens. Lastly, they provide recommendations on coagulation management in the context of acute-on-chronic liver failure, acute liver decompensation, and specific aspects related to the patient undergoing liver transplantation.

Portal Vein Thrombosis in Liver Transplantation: A Retrospective Cohort Study

Portal vein thrombosis was considered a contraindication for liver transplantation. This study analyzes the perioperative complications and survival of liver transplant patients with portal vein thrombosis (PVT). A retrospective observational cohort study of liver transplant patients was conducted. The outcomes were early mortality (30 days) and patient survival. A total of 201 liver transplant patients were identified and 34 (17%) patients with PVT were found. The most frequent extension of thrombosis was Yerdel 1 (58.8%), and a portosystemic shunt was identified in 23 (68%) patients. Eleven patients (33%) presented any early vascular complication, PVT being the most frequent (12%). The multivariate regression analysis showed a statistically significant association between PVT and early complications (OR = 3.3, 95% confidence interval 1.4-7.7; p = 0.006). Moreover, early mortality was observed in eight patients (24%), of which two (5.9%) presented Yerdel 2. For Yerdel 1, patient survival according to the extent of thrombosis was 75% at 1 year and 3 years, while for Yerdel 2, it was 65% at 1 year, and 50% at 3 years (p = 0.04). Portal vein thrombosis significantly influenced early vascular complications. Furthermore, portal vein thrombosis Yerdel 2 or higher impacts the survival of liver grafts in the short and long term.

Portal Vein Recanalization-Transjugular Intrahepatic Portosystemic Shunt (PVR-TIPS) Facilitates Liver Transplantation in Cirrhotic Patients with Occlusive Portal Vein Thrombosis

Portal vein thrombosis (PVT) is a heterogeneous condition with multiple possible etiologies and to varying degrees has historically limited candidacy for liver transplant (LT) in the cirrhotic patient population due to resultant difficulties in constructing a robust portal vein anastomosis. While intraoperative approaches to managing PVT are well-described, methods which approximate normal portal physiology are not always feasible depending on the extent of PVT, and other nonphysiologic techniques are linked with substantial morbidity and poor long-term outcomes. Portal vein recanalization-transjugular intrahepatic portosystemic shunt (PVR-TIPS) creation is an efficacious method of restoring physiologic portal flow in cirrhotic patients prior to LT allowing for end-to-end PV anastomosis, and is the product of decades-long institutional expertise in TIPS/LT and the support of a multidisciplinary liver tumor board. To follow is a review of the pertinent pathophysiology of PVT in cirrhosis, the rationale leading to the development and subsequent evolution of the PVR-TIPS procedure, technical lessons learned, and a summary of outcomes to date.

Splenic artery steal syndrome after liver transplantation - prophylaxis or treatment?: A case report and literature review

Splenic artery steal syndrome (SASS) is a cause of graft hypoperfusion leading to the development of biliary tract complications, graft failure, and in some cases to retransplantation. Its management is still controversial since there is no universal consensus about its prophylaxis and consequently treatment. We present a case of SASS that occurred 48 hours after orthotopic liver transplantation (OLTx) in a 56-year-old male patient with alcoholic cirrhosis and severe portal hypertension, and who was successfully treated by splenic artery embolization. A literature search was performed using the PubMed database, and a total of 22 studies including 4,789 patients who underwent OLTx were relevant to this review. A prophylactic treatment was performed in 260 cases (6.2%) through splenic artery ligation in 98 patients (37.7%) and splenic artery banding in 102 (39.2%). In the patients who did not receive prophylaxis, SASS occurred after OLTx in 266 (5.5%) and was mainly treated by splenic artery embolization (78.9%). Splenic artery ligation and splenectomies were performed, respectively, in 6 and 20 patients (2.3% and 7.5%). The higher rate of complications registered was represented by biliary tract complications (9.7% in patients who received prophylaxis and 11.6% in patients who developed SASS), portal vein thrombosis (respectively, 7.3% and 6.9%), splenectomy (4.8% and 20.9%), and death from sepsis (4.8% and 30.2%). Whenever possible, prevention is the best way to approach SASS, considering all the potential damage arising from an arterial graft hypoperfusion. Where clinical conditions do not permit prophylaxis, an accurate risk assessment and postoperative monitoring are mandatory.

The role of shear wave elastography in differentiation between benign and malignant portal vein thrombosis in hepatocellular carcinoma

Background

Hepatocellular carcinomas (HCC) most commonly complicate liver cirrhosis and it may coexist with malignant portal vein invasion (PVI) that minimizes its possible treatment opportunities and negatively affects its prognosis. However, liver cirrhosis may also be associated with non-tumoral portal vein thrombosis (PVT) particularly in decompensated cirrhosis. Thus, discrimination between tumoral and non-tumoral PVT most preferably by non-invasive imaging techniques is mandatory before treatment decision. Based on the concept of changing tissue elasticity according to tissue pathological changes, Shear wave elastography (SWE) could quantitatively assess tissue stiffness in malignant PVI. We aimed in this work to evaluate the performance of SWE as a novel fast non-invasive diagnostic modality for malignant PVI in cirrhotic patients with HCC.

Results

Seventy-eight HCC patients with PVT included in this prospective cross-sectional study, tumoral and non-tumoral PVT were differentiated using triphasic CT and/or dynamic MRI, then SWE was blindly and independently done for all included patients. non-tumoral PVT was present in 21.8% of our HCC patients mostly in decompensated cirrhosis. All of our evaluated predictor factors were evaluated by univariate logistic regression analysis to identify the significant factors in prediction of malignant PVI (SWE, AFP, HCC size, HCC multi-focality, and PVD). By using the multivariate logistic regression we identified that the most independent significant factors were SWE and PVD (sig.: 0.012 and 0.045 respectively). SWE was evaluated versus the criteria of PVT and we found that malignant PVI has significant higher SWE values than benign non-tumoral PVT (sig: 0.012). Two cutoff values were calculated for SWE using ROC curve; the 1st cutoff point was selected to rule in malignant PVI for values ≥ 13 kps, while the 2nd cutoff point was selected to rule out malignant PVI for values ≤ 9 kps with a significant discriminatory performance (AUC: 0.984; sig: 0.000).

Conclusions

SWE could be used as a novel fast and non-invasive indicator of malignant portal vein invasion in cirrhotic patients with HCC especially for values ≥ 13 kps and particularly if coexists with larger values of PVD and AFP.

Meta-analysis and systematic review: Prevalence, graft failure, mortality, and post-operative thrombosis in liver transplant recipients with pre-operative portal vein thrombosis

AIMS

This study seeks to evaluate the association between pre-transplant portal vein thrombosis (PVT) and overall survival, graft failure, waitlist mortality, and post-operative PVT after liver transplantation.

METHODS

A conventional pairwise meta-analysis between patients with and without pre-transplant PVT was conducted using hazard ratios or odds ratios where appropriate.

RESULTS

Prevalence of preoperative PVT was 11.6% (CI 9.70-13.7%). Pre-operative PVT was associated with increased overall mortality (HR 1.45, 95% CI 1.27-1.65) and graft loss (HR 1.58, 95% CI 1.34-1.85). In particular, grade 3 (HR 1.59, 95% CI 1.00-2.51) and 4 (HR 2.24, 95% CI 1.45-3.45) PVT significantly increased mortality, but not grade 1 or 2 PVT. Patients with PVT receiving living donor (HR 1.54, 95% CI 1.24-1.91) and deceased donor (HR 1.52, 95% CI 1.21-1.92) liver transplantation had increased mortality, with no significant difference between transplant types (P = .13). Furthermore, pre-transplant PVT was associated with higher occurrence of post-transplant PVT (OR 5.06, 95% CI 3.89-6.57). Waitlist mortality was not significantly increased in patients with pre-transplant PVT.

CONCLUSION

Graft failure, mortality, and post-operative PVT are more common in pre-transplant PVT patients, especially in grade 3 or 4 PVT. Prophylactic anticoagulation can be considered to reduce re-thrombosis and improve survival.

Influence of portal vein occlusion on portal flow and liver elasticity in an animal model

Hepatic fibrosis causes an increase in liver stiffness, a parameter measured by elastography and widely used as a diagnosis method. The concomitant presence of portal vein thrombosis (PVT) implies a change in hepatic portal inflow that could also affect liver elasticity. The main objective of this study is to determine the extent to which the presence of portal occlusion can affect the mechanical properties of the liver and potentially lead to misdiagnosis of fibrosis and hepatic cirrhosis by elastography. Portal vein occlusion was generated by insertion and inflation of a balloon catheter in the portal vein of four swines. The portal flow parameters peak flow (PF) and peak velocity magnitude (PVM) and liver mechanical properties (shear modulus) were then investigated using 4D-flow MRI and MR elastography, respectively, for progressive obstructions of the portal vein. Experimental results indicate that the reduction of the intrahepatic venous blood flow (PF/PVM decreases of 29.3%/8.5%, 51.0%/32.3% and 83.3%/53.6%, respectively) measured with 50%, 80% and 100% obstruction of the portal vein section results in a decrease of liver stiffness by 0.8% ± 0.1%, 7.7% ± 0.4% and 12.3% ± 0.9%, respectively. While this vascular mechanism does not have sufficient influence on the elasticity of the liver to modify the diagnosis of severe fibrosis or cirrhosis (F4 METAVIR grade), it may be sufficient to attenuate the increase in stiffness due to moderate fibrosis (F2-F3 METAVIR grades) and consequently lead to false-negative diagnoses with elastography in the presence of PVT.

Portal vein thrombosis and renal dysfunction: a national comparative study of liver transplant recipients for NAFLD versus alcoholic cirrhosis

The prevalence of portal vein thrombosis (PVT), renal dysfunction (RD), and simultaneous PVT/RD in liver transplantation (LT) is poorly understood. We analyzed the prevalence of PVT, RD, simultaneous PVT/RD, and the outcomes of adult recipients of LT for nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) between 2006 and 2016 in the United States. We found that the prevalence of PVT (7.2% → 11.3%), RD (33.8% → 39.2%), and simultaneous PVT/RD (2.4% → 4.5%) has increased significantly over the study period (all P‐values <0.05). NAFLD patients had a higher proportion of PVT (14.8% vs. 9.2%), RD (45.0% vs. 42.1%), and simultaneous PVT/RD (6.5% vs. 3.9%; all P‐values <0.05). 90‐day mortality was 3.8%, 6.3%, 6.8%, and 9.8% for PVT(−)/RD(−), PVT(−)/RD(+), PVT(+)/RD(−), and PVT(+)/RD(+) recipients, respectively (P < 0.01). 5‐year survival was 82.1%, 75.5%, 74.8%, and 71.1% for PVT(−)/RD(−), PVT(−)/RD(+), PVT(+)/RD(−), and PVT(+)/RD(+) recipients, respectively (P < 0.05). In conclusion, the prevalence of PVT, RD, and simultaneous PVT/RD has increased among LT recipients, especially for those with NAFLD. The short‐ and long‐term outcomes of recipients with PVT, RD, and simultaneous PVT/RD were inferior to patients without those risk factors irrespective of their indication for LT. No differences in patient outcomes were found between ALD and NAFLD recipients after stratification by risk factors.

Sonography of liver transplantation

Orthotopic liver transplant (OLT) is established as the definitive treatment of choice for end stage liver disease. Over the years, refined surgical techniques as well as advancements in organ preservation and immunosuppressive regimens have improved graft and patient survival rates. Imaging has also contributed to improved graft and patient survival. Ultrasound is the initial investigation of choice for evaluation of post-transplant anatomy and for identifying early complications. A thorough knowledge of surgical techniques and normal post-operative appearance of the OLT is needed to accurately identify and characterize graft complications. The objective of this article is to review the sonographic findings of normal liver transplant as well as post-operative complications. Indications and contraindications for OLT as well as different surgical techniques will also be briefly reviewed.

Imaging post liver transplantation part I: vascular complications

Liver transplantation continues to rise in frequency, with over 1,000 procedures performed in the UK in 2018. Complications are increasingly uncommon but when they occur, early recognition and intervention is vital to save grafts. Imaging after the perioperative period is often performed at patients' local hospitals meaning that all radiologists and sonographers need to have an understanding of how to assess a transplant liver. Part I of this series will focus on vascular complications, including the normal postoperative vascular anatomy following liver transplantation, normal post-transplantation vascular imaging findings and abnormal findings that may prompt further investigation. Vascular complications following liver transplantation will be illustrated using a collection of cases.

Selection for Liver Transplantation: Indications and Evaluation

Purpose of Review

Liver transplantation is an important therapeutic option for patients with life-limiting liver disease, which may present in the form of acute liver failure, end-stage chronic liver disease, primary hepatic cancers, or inborn metabolic disorders. While significant strides have been made with respect to liver transplantation outcomes, the practice is constrained by an organ supply/demand mismatch. The purpose of this review, therefore, is to review the general indications and contraindication to liver transplantation, and to provide an overview of the transplant evaluation process. These considerations ultimately shape the specific criteria for patient selection, which will continue to evolve as means are developed to expand the donor pool, improve surgical techniques, broaden indications for safe transplant, and extend the lifetime of a graft.

Recent Findings

Selected patients with unresectable hilar cholangiocarcinoma may be candidates for liver transplantation. Patients over 65 years may be transplant candidates if they possess a favorable comorbidity profile. Patients at body mass index extremes (≥ 40 or < 18.5) have increased post-transplant mortality and require nutritional evaluation.

Summary

Liver transplantation may be life saving for patients with acute liver failure or end-stage liver disease. It is therefore critical for healthcare providers caring for patients with liver disease to be familiar with the general indications for transplantation and to know when it is appropriate or inappropriate to refer for transplant evaluation.

Case Report: Portal Vein Thrombosis, Surgical Alternatives in Liver Transplantation

INTRODUCTION

Liver transplant remains a surgical challenge in cases of portal vein thrombosis. Ten percent of patients listed for liver transplant have this diagnosis preoperatively. Although several techniques of portal revascularization are available, sometimes the best result is not achieved, depending on the extent of thrombosis.

OBJECTIVE

The aim of this article is to report our experience in 2 particular cases of liver transplant with portal vein thrombosis.

MATERIAL AND METHODS

We present the cases of 2 patients with partial portal thrombosis that extended to the porto-spleno-mesenteric system. The first case is a 36-year-old woman with recurrence of autoimmune liver disease requiring a second graft; the second case concerns a 64-year-old man with alcoholic liver cirrhosis.

RESULTS

Both patients had a splenorenal shunt. A portal bypass with a Y venous graft was performed using the cavoiliac veins of the donor. The anastomosis was performed to the superior mesenteric and left renal veins.

DISCUSSION AND CONCLUSIONS

These clinical cases demonstrate that portal vein thrombosis is not an absolute contraindication for transplantation and that surgical alternatives exist in cases of grade III portal vein thrombosis.

Perioperative management of antithrombotic treatment

End-stage liver disease is characterized by multiple and complex alterations of hemostasis that are associated with an increased risk of both bleeding and thrombosis. Liver transplantation further challenges the feeble hemostatic balance of patients with decompensated cirrhosis, and the management of antithrombotic treatment during and after transplant surgery, which is particularly difficult. Bleeding was traditionally considered the major concern during and early after surgery, but it is increasingly recognized that transplant recipients may also develop thrombotic complications. Pathophysiology of hemostatic complications during and after transplantation is multifactorial and includes pre-, intra-, and postoperative risk factors. Risk stratification is important, as it helps the identification of high-risk recipients in whom antithrombotic prophylaxis should be considered. In recipients who develop thrombosis during or after surgery, prompt treatment is indicated to prevent graft failure, retransplantation, and death.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Utility of Transjugular Intrahepatic Portosystemic Shunt Placement for Maintaining Portal Vein Patency in Candidates on Wait Lists Who Develop Thrombus

OBJECTIVES

Although no longer a contraindication to liver transplant, portal vein thrombosis may lead to longer operative time and complexities in venous reconstruction. Strategies to maintain preoperative patency include systemic anticoagulation and/or transjugular intrahepatic portosystemic shunt placement. The former may not be ideal in cirrhotic patients prone to luminal gastrointestinal tract bleeding, and factors that predict improvements in portal vein thrombosis with the latter have not been well defined. Our goal was to evaluate the effectiveness of transjugular intrahepatic portosystemic shunt placement as monotherapy to improve and/or resolve portal vein thrombosis in otherwise eligible liver transplant candidates with partial or complete portal vein thrombosis and to identify factors predicting success.

MATERIALS AND METHODS

We identified 30 patients from 2010 to 2015 who had transjugular intrahepatic portosystemic shunt placementfor primary indication to maintain portal vein patency.

RESULTS

The main portal vein was completely thrombosed in 5 of 30 (16.6%), nearly completely thrombosed in 9 of 30 (30%), and partially thrombosed in 16 patients (53.3%). Twenty-four patients (80%) had improvement and/or resolution of portal vein thrombosis after transjugular intrahepatic portosystemic shunt placement, with 18 of these (75%) having complete resolution. All 5 patients (20.8%) with complete thrombosis had improvement/resolution of portal vein thrombosis. Nine patients (30%) required hospitalization within 3 months for hepatic encephalopathy. There were 3 deaths (10%) not related to transjugular intrahepatic portosystemic shunt placement (10%). Nine patients underwent liver transplant after shunt placement (median 2.9 mo; range, 0.3-32 mo); all 9 received endto-end anastomosis without need for intraoperative thrombectomy.

CONCLUSIONS

Transjugular intrahepatic portosystemic shunt placement may be effective as monotherapy for maintaining or restoring portal vein patency in selected livertransplant candidates, even in those with complete portal vein thrombosis. Further studies are needed to define potential responders to this approach.

Novel classification of non-malignant portal vein thrombosis: A guide to surgical decision-making during liver transplantation

Non-tumoral portal vein thrombosis (PVT) is present at liver transplantation in 5% to 26% of cirrhotic patients, and the prevalence of complex PVT as defined here (grade 4 Yerdel, and grade 3,4 Jamieson and Charco) has been reported in 0% to 2.2%. Adequate portal inflow is mandatory to ensure graft and patient survival after liver transplantation. With time, the proposed classifications of non-tumoral chronic PVT have evolved from being anatomy-based, to also incorporating functional parameters. However, none of the currently proposed classifications are directed towards decision-making, regarding the choice of inflow to the graft during transplantation and the outcomes thereof. The present scoping review i) addresses the limits of the currently available classifications in terms of surgical decisiveness, ii) clarifies the concept of physiological or non-physiological portal inflow reconstruction, and subsequently, iii) proposes a new classification of non-tumoral PVT in candidates for liver transplantation; to help tailor the surgical strategy to an individual patient, in order to provide portal inflow to the graft together with control of prehepatic portal hypertension whenever feasible.

Incidence, predictive factors and clinical significance of development of portal vein thrombosis in cirrhosis: A prospective study

BACKGROUND AND AIMS

The role of portal vein thrombosis (PVT) in the natural history of cirrhosis is controversial. There are few prospective studies validating risk factors for development of PVT. We analysed the incidence, factors associated with PVT development and its influence on cirrhosis decompensations and orthotopic liver transplant (OLT)-free survival.

METHODS

In this prospective observational study between January 2014 and March 2019, 445 consecutive patients with chronic liver disease were screened and finally 241 with cirrhosis included. Factors associated with PVT development and its influence on cirrhosis decompensations and OLT-free survival by time dependent covariate coding were analysed.

RESULTS

Majority of patients belonged to Child-Pugh class A 184 (76.3%) and the average MELD score was 10 ± 5. Previous cirrhosis decompensations occurred in 125 (52.1%), 63 (26.1%) were on NSBB and 59 (27.2%) had undergone banding for bleeding prophylaxis. Median follow-up was 29 (1-58) months. Cumulative incidence of PVT was 3.7% and 7.6% at 1 and 3 years. Previous decompensation of cirrhosis and low platelet counts but not NSBB independently predicted the development of PVT. During follow-up, 82/236 (34.7%) patients developed cirrhosis decompensations. OLT-free survival was 100% and 82.8% at 3 years, with and without PVT respectively. MELD score, but not PVT, independently predicted cirrhosis decompensations (HR 1.14; 95%CI:1.09-1.19) and OLT-free survival (HR 1.16;95%CI:1.11-1.21).

CONCLUSION

Previous decompensations of cirrhosis and thrombocytopenia predict PVT development in cirrhosis suggesting a pathophysiologic role for severity of portal hypertension. PVT development did not independently predict cirrhosis decompensations or lower OLT-free survival.

Portal Vein Thrombosis in a Patient with Hereditary Antithrombin Deficiency

Portal vein thrombosis (PVT) has been reported in many patients with and without liver cirrhosis. The portal vein is a rare site of thrombosis, and various conditions can predispose an individual to PVT. Among those conditions, hereditary thrombophilia has been increasingly reported recently. We herein report the case of a non-cirrhotic 30-year-old man who developed acute PVT with hereditary antithrombin deficiency. Antithrombin (AT) replacement therapy was required along with heparin. Given our experience with this case, we believe that a screening test for prothrombotic disorders, such as AT deficiency, should be considered in cases of PVT.

Outcome of Liver Transplant Patients With Intraoperative-Detected Portal Vein Thrombosis: A Retrospective Cohort Study in Shiraz, Iran

OBJECTIVES

We aimed to determine outcomes and predictors of intraoperative-detected portal vein thrombosis in liver transplant recipients.

MATERIALS AND METHODS

We retrospectively analyzed 806 adult liver transplant recipients from Shiraz, Iran, to determine those with intraoperative-detected portal vein thrombosis. Patients with this complication were compared with age- and sex-matched patients without this complication. Background diseases, surgery parameters, hospital admission, reoperation, rethrombosis, acute rejection, and use of antico-agulants were assessed. Cox proportional hazards, logistic regression, and random classification forest and random survival forest plots were used for data analyses.

RESULTS

Mean age of patients was 44.7 ± 13.2 years. Patients with intraoperative-detected portal vein thrombosis (n = 91; 11.3%) had mortality ratio of 2.9 (range, 1.0-8.6) and 2-year survival of 78% versus 2-year survival rate of 92% in patients without this disease. Median time of survival in patients with this complication who died was 2 weeks versus 10 months in patients who died and did not have this complication. Random classification forest plots showed that high fasting blood sugar, autoimmune hepatitis, low prothrombin time, and cryptogenic cirrhosis were (in order) the main predictors of this complication. Random survival forest plots revealed that low prothrombin time, having intraoperative-detected portal vein thrombosis, Model for End Stage Liver Disease score, primary sclerosing cholangitis, diabetes mellitus, and hepatocellular carcinoma were (in order) the main predictors of death in liver transplant recipients. Low body mass index was associated with mortality in patients with intraoperative-detected portal vein thrombosis (by Cox proportional hazards).

CONCLUSIONS

One of every 9 liver transplant patients had intraoperative-detected portal vein thrombosis. Hazard of death was 2.9, and death occurred far earlier in patients with this complication. Improvements in diabetes mellitus care, prothrombin time, Model for End-Stage Liver Disease score, and body mass index may improve outcomes of these patients.

Perioperative hemostatic management in the cirrhotic patient: a position paper on behalf of the Liver Intensive Care Group of Europe (LICAGE)

Recent data demonstrated that amongst patients undergoing elective surgery the prevalence of cirrhosis is 0.8% equating to approximately 25 million cirrhotic patients undergoing surgery each year worldwide. Overall, the presence of cirrhosis is independently associated with 47% increased risk of postoperative complications and over two and a half-increased risk of in-hospital mortality in patients undergoing elective surgery. In particular, perioperative patients with chronic liver disease have long been assumed to have a major bleeding risk on the basis of abnormal results for standard tests of hemostasis. However, recent evidence outlined significant changes to traditional knowledge and beliefs and, nowadays, with more sophisticated laboratory tests, it has been shown that patients with chronic liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. The aim of this paper endorsed by the Liver Intensive Care Group of Europe was to provide an up-to-date overview of coagulation management in perioperative patients with chronic liver disease focusing on patient blood management, monitoring of hemostasis, and current role of hemostatic agents.

Portal vein thrombosis in patients with liver cirrhosis and its impact on early and long-term outcomes after liver transplantation

AIM

Portal vein thrombosis (PVT) is a common complication amongst patients with liver cirrhosis. The PVT risk factors and its impact on post liver transplant outcome has not been well defined, yet. This study aimed to investigate PVT prevalence, its risk factors and influence on early and long-term outcomes after liver transplantation.

METHODS

Adult (>18 years) patients with liver cirrhosis undergoing liver transplantation between March 2013 to March 2015 were included. Presence or absence of PVT was recorded at transplant. PVT risk factors in patients with liver cirrhosis and its impact on early and long-term outcomes were analysed.

RESULTS

Portal vein thrombosis was diagnosed in 174 patients (17.3%). Large oesophageal varices (grade II and III vs grade I) (OR: 2.5; 95% CI: 1.46-4.26; P = 0.001), diabetes mellitus before transplantation (OR: 2.03; 95% CI: 1.13-3.64; P = 0.017) and cryptogenic-NASH (OR: 1.36; 95% CI: 1.08-1.72; P = 0.008) as a cause of underlying liver disease were the independent risk factors for PVT. PVT (OR: 2.05; 95% CI: 1.10-3.81; P = 0.023) was an independent predictor of early (within 90 days) posttransplant mortality, but did not influence long-term survival.

CONCLUSION

Portal vein thrombosis prevalence is high in pretransplant period. NASH related cirrhosis and diabetes mellitus might be risk factors for PVT. More intense screening of these patients for PVT is warranted.

Portal vein thrombosis in cirrhosis: diagnosis, natural history, and therapeutic challenges

Portal vein thrombosis (PVT) is a frequent complication in cirrhosis and its prevalence increases with disease severity. Several factors are involved in the development and progression of PVT. The challenge for the management of PVT is the precise evaluation of the bleeding risk as opposed to life-threatening extension of thrombosis. Nevertheless, the impact on the progression and outcome of liver disease is unclear. A critical evaluation of the available data discloses that treating PVT in cirrhotics is safe and effective. However, there are open issues, such as which anticoagulant could represent a safer therapeutic option, and when and for how long this treatment should be administered to cirrhotic patients with PVT.

Successful Treatment of a Patient With Diffuse Portosplenomesenteric Thrombosis Using a Pericholedochal Varix for Portal Flow Reconstruction During Deceased Donor Liver Transplantation: A Case Report

Portal vein thrombosis remains a challenging issue in liver transplantation. When thrombectomy is not feasible due to diffuse portosplenomesenteric thrombosis, other modalities are adapted such as the use of a jump graft or portal tributaries or even multivisceral transplantation. For patients with diffuse thrombosis of the splanchnic venous system, a large pericholedochal varix can be a useful vessel for providing splanchnic blood flow to the graft and for relieving portal hypertension. We report our experience of successfully treating a patient with diffuse portosplenomesenteric thrombosis using a pericholedochal varix for portal flow reconstruction during deceased donor liver transplantation and eventually preventing unnecessary multivisceral transplantation. A 56-year-old man diagnosed with liver cirrhosis due to hepatitis B underwent deceased donor liver transplantation due to refractory ascites. Preoperative imaging revealed diffuse portosplenomesenteric thrombosis with large amount of ascites. During the operation, dissection of the main portal vein was not possible due to the development of multiple large pericholedochal varices and cavernous change of the main portal vein. After outflow reconstruction, portal inflow was restored by anastomosing the graft portal vein to a large pericholedochal varix. Postoperatively, although abdominal computed tomography scan showed stenosis of portal vein anastomosis site, liver function tests improved, and Doppler sonogram revealed no flow disturbance. During follow-up, the patient repeatedly developed hydrothorax and ascites. In addition, stenosis of the portal vein anastomosis and thrombosis of the portomesenteric system still remained. The patient underwent transhepatic portal vein stent insertion. After portal vein stent insertion, hydrothorax and ascites improved and the extent of thrombosis of the portomesenteric system decreased without anticoagulation therapy. In conclusion, enlarged pericholedochal varix in patients with totally obliterated splanchnic veins can be a source of useful inflow to restore portal flow and decrease the extent of thrombosis, thereby preventing unnecessary multivisceral transplantation.

Pretransplantation Portal Vein Recanalization and Transjugular Intrahepatic Portosystemic Shunt Creation for Chronic Portal Vein Thrombosis: Final Analysis of a 61-Patient Cohort

PURPOSE

To report the final analysis of the safety and efficacy of portal vein (PV) recanalization (PVR) and transjugular intrahepatic portosystemic shunt (TIPS) creation (PVR-TIPS) in patients with PV thrombosis (PVT) in need of liver transplantation.

MATERIALS AND METHODS

Sixty-one patients with cirrhosis and PVT underwent PVR-TIPS to improve transplantation candidacy. Median patient age was 58 years (range, 22-75 y), and median pre-TIPS Model for End-Stage Liver Disease score was 14 (range, 7-42). The most common etiologies of cirrhosis were nonalcoholic fatty liver disease in 18 patients (30%) and hepatitis C in 13 patients (21%). Twenty-seven patients (44%) had partial PVT, and 34 patients (56%) had complete thrombosis. Forty-nine patients (80%) had Yerdel grade 2 PVT, and 12 (20%) had Yerdel grade 3 PVT. Twenty-nine patients (48%) had cavernous transformation of the PV.

RESULTS

PVR-TIPS was technically successful in 60 of 61 patients (98%). PV/TIPS patency was maintained in 55 patients (92%) at a median follow-up of 19.2 months (range, 0-105.9 mo). Recurrent PV/TIPS thrombosis occurred in 5 patients (8%), all of whom initially presented with complete PVT. The most common adverse events were TIPS stenosis in 13 patients (22%) and transient encephalopathy in 11 patients (18%). Twenty-four patients (39%) underwent transplantation, 23 of whom (96%) received an end-to-end anastomosis. There were no cases of recurrent PVT following transplantation, with a median imaging follow-up of 32.5 months (range, 0.4-75.4 mo). Five-year overall survival rate was 82%.

CONCLUSIONS

PVR-TIPS is a safe, effective, and durable treatment option for patients with chronic PVT who need liver transplantation.

Reno-portal shunt for liver transplant, an alternative inflow for recipients with grade III-IV portal vein thrombosis: Tips for a better outcome

INTRODUCTION

Portal vein thrombosis (PVT) poses an extremely difficult problem in cirrhotic patients who are in need of a liver transplant. The prevalence of PVT in patients with cirrhosis ranges from 0.6% to 26% Nery et al. (2015) [1]. The presence of PVT is associated with more technically difficult liver transplant and in certain cases can be a contraindication to liver transplant. The only option for these patients with extensive PVT would be a multi-visceral transplant, the later unfortunately has a much higher morbidity and mortality compared to liver only transplant Smith et al. (2016) [2]. An alternative approach is needed to provide a safe and reliable outcome.

PRESENTATION OF CASE

In this case series, we present our experience with reno-portal shunt as an alternative inflow for the liver allograft.

DISCUSSION

This approach appears to be safe with good long-term outcome.Although this technique has been described before, we provide additional considerations that produced good outcomes in our patients.

CONCLUSION

We believe that meticulous preoperative planning with high-resolution triple phase CT imaging with a measurement of the diameter of the spleno-renal shunt along with a duplex scan measuring flow through the shunt is key to a successful transplantation. Moreover, appropriate donor liver size is also of extreme importance to avoid portal hypoperfusion.

Significance of measured intraoperative portal vein flows after thrombendvenectomy in deceased donor liver transplantations with portal vein thrombosis

Adequate portal vein (PV) flow in liver transplantation is essential for a good outcome, and it may be compromised in patients with portal vein thrombosis (PVT). This study evaluated the impact of intraoperatively measured PV flow after PV thrombendvenectomy on outcomes after deceased donor liver transplantation (DDLT). The study included 77 patients over a 16-year period who underwent PV thrombendvenectomy with complete flow data. Patients were classified into 2 groups: high PV flow (>1300 mL/minute; n = 55) and low PV flow (≤1300 mL/minute; n = 22). Postoperative complications and graft survival were analyzed according to the PV flow. The 2 groups were similar in demographic characteristics. Low PV flow was associated with higher cumulative rates of biliary strictures (P = 0.02) and lower 1-, 2-, and 5-year graft survival (89%, 85%, and 68% versus 64%, 55%, and 38%, respectively; P = 0.002). There was no difference in the incidence of postoperative PVT between the groups (1.8% versus 9.1%; P = 0.19). No biliary leaks or hepatic artery thromboses were reported in either group. By multivariate analyses, age >60 years (hazard ratio [HR], 3.04, 95% confidence interval [CI], 1.36-6.82; P = 0.007) and low portal flow (HR, 2.31; 95% CI, 1.15-4.65; P = 0.02) were associated with worse survival. In conclusion, PV flow <1300 mL/minute after PV thrombendvenectomy for PVT during DDLT was associated with higher rates of biliary strictures and worse graft survival. Consideration should be given to identifying reasons for low flow and performing maneuvers to increase PV flow when intraoperative PV flows are <1300 mL/minute. Liver Transplantation 23 1032-1039 2017 AASLD.

Incidence and clinical presentation of portal vein thrombosis in cirrhotic patients

BACKGROUND

Portal vein thrombosis (PVT) is due to many risk factors, but its pathogenesis is still not clearly understood. To identify the risk factors for PVT, we analyzed the clinical characteristics and complications associated with PVT in cirrhotic patients.

METHODS

We studied patients with liver cirrhosis who were admitted to our unit from April 2009 to December 2014. The patients were divided into the PVT and non-PVT groups, and were compared by variables including gender, age, the etiology of cirrhosis, stage of cirrhosis, complications, imaging, and treatment.

RESULTS

PVT was found in 45 (9.8%) of 461 cirrhotic patients admitted to our hospital. Most patients (45.9%) had hepatitis B virus (HBV)-related cirrhosis, with a similar distribution of etiologies between the groups. However, there was no positive relationship between PVT and etiologies of cirrhosis. Most patients (71.5%) were in the stage of hepatic decompensation. No statistically significant differences were found in complications including esophageal varices, ascites, and hepatic encephalopathy between the groups. However, there was a significant positive correlation between hepatocellular carcinoma (HCC) and PVT (P<0.01). In 30 patients with PVT, thrombosis occurred in the portal vein and/or portal branches, 37.8% were diagnosed on ultrasound.

CONCLUSIONS

The incidence of PVT was 9.8%, mainly in patients with HBV-related cirrhosis. The development of PVT was associated with the severity of liver disease and HCC.

Use of Left Gastric Vein as an Alternative for Portal Flow Reconstruction in Liver Transplantation

Portal vein thrombosis is observed in up to 10% of liver transplant candidates, hindering execution of the procedure. A dilated gastric vein is an alternative to portal vein reconstruction and decompression of splanchnic bed. We present two cases of patients with portal cavernoma and dilated left gastric vein draining splanchnic bed who underwent liver transplantation. The vein was dissected and sectioned near the cardia; the proximal segment was ligated with suture and the distal segment was anastomosed to the donor portal vein. Gastroportal anastomosis is an excellent option for portal reconstruction in the presence of thrombosis or hypoplasia. It allows an adequate splanchnic drainage and direction of hepatotrophic factors to the graft.

Single-center experience of living donor liver transplantation in patients with portal vein thrombosis

BACKGROUND

Portal vein thrombosis (PVT) is a relative contraindication in living donor liver transplantation (LDLT). We investigated the long-term outcome of adult patients with PVT in LDLT.

METHODS

Between 2004 and 2009, 471 cases of adult LDLT were performed and 56 patients had PVT (11.8%). Thrombectomy was attempted using a modified eversion technique. We evaluated the outcome of patients with PVT according to grade and compared with no-PVT patients.

RESULTS

There was no difference in terms of age, gender, Child-Pugh score, MELD score, proportion of malignance, operation time, and total amount of transfused blood. Complete thrombectomy was successful in 73.2% (41/56), partial thrombectomy in 26.8% (15/56), and one case needed jump graft for portal vein reconstruction. Among patients with partial thrombectomy, when the PV velocity was above 20 cm/s, the remnant thrombus disappeared in 46%. The rate of PV complication was statistically not different (8.9% vs 3.4%, P=.062). Five-year survival of mild PVT was 69.3%, 60.6% for severe PVT, and 80.4% for no-PVT (P=.059).

CONCLUSIONS

Eversion thrombectomy by modified technique is feasible in most cases of PVT. Good long-term outcome may be expected in LDLT with PVT.

Management of portal vein thrombosis in cirrhosis: an update

BACKGROUND

Portal vein thrombosis (PVT) is a complication of cirrhosis. However, whether PVT worsens cirrhosis outcome is a debated issue.

AIM

To report an update on the management of PVT.

METHODS

A review was performed on the outcome, prevention, and treatment of PVT.

RESULTS

Some studies suggest that PVT could worsen the rate of hepatic decompensation and survival of cirrhosis, whereas others report a non-negative impact of PVT in the outcome of cirrhosis. Therefore, the prognostic value of PVT in cirrhosis remains a gray zone. One single randomized-controlled trial reported that enoxaparin could prevent PVT, delay the occurrence of hepatic decompensation, and improve survival. However, no further study data confirmed this assumption and the issue is not actually generalizable. Numerous studies report that anticoagulation determines a relatively high rate of portal vein recanalization in cirrhotics PVT. However, further data are warranted to confirm the risk-to-benefit of anticoagulation, especially bleeding. Transjugular intrahepatic portosystemic shunt (TIPS) has been reported to be effective as a treatment of PVT in cirrhosis, with the advantage of avoiding the risk of bleeding linked to anticoagulation. However, there are no data comparing TIPS with anticoagulation as a treatment of PVT in cirrhosis. Furthermore, there is no evidence on whether both anticoagulation and TIPS improve survival.

CONCLUSION

It is uncertain whether PVT affects cirrhosis outcome. Further data are needed to weigh the risk/benefit ratio of enoxaparin for the prevention of PVT in cirrhosis. Anticoagulation or TIPS should probably be indicated in liver transplantation candidates, but avoided in patients not suitable for liver transplantation and with an otherwise poor prognosis. Future studies should evaluate which subgroup of cirrhotics with PVT may benefit from treatment. Management of PVT in cirrhosis should be personalized.

The ischemic liver cirrhosis theory and its clinical implications

The canonical pathway theory of cirrhosis addresses inflammation as the main driver of hepatic fibrogenesis in hepatitis, so needing a further hypothesis for etiologies missing inflammation, for which parenchymal extinction is postulated. The present paper reports an alternative hypothesis suggesting a central role of micro-vascular ischemia in fibrogenesis and cirrhosis development, whatever is the aetiology of liver chronic injury. In fact, since chronic liver injury could finally result in endothelial damage and micro-vascular thrombosis, leading to a trigger of inappropriate hepatocyte proliferation and fibrosis, finally cirrhosis development could arise from chronic micro-vascular ischemia. Recently, some important confirmation of this hypothesis has been reported. In fact, in a murine experimental model of congestive hepatopathy, it was found that chronic hepatic congestion leads to sinusoidal thrombosis and strain, which in turn promote hepatic fibrosis. Furthermore, a study on a murine model of cirrhosis reported enoxaparin to reduce hepatic vascular resistance and portal pressure by having a protective role against fibrogenesis. In conclusion, the hypothesis giving a central role of micro-vascular ischemia in fibrogenesis and cirrhosis development could change the clinical scenario of chronic liver disease and have several main implications on management of various liver disease.

A comparative study of two anti-coagulation plans on the prevention of PVST after laparoscopic splenectomy and esophagogastric devascularization

Cirrhosis and portal hypertension (PH) has a high incidence in China. Laparoscopic splenectomy and esophagogastric devascularization (LS + ED) was confirmed as an effective and safe surgical approach. But compared to open surgery (OS + ED), the rate of portal vein system thrombosis (PVST) was found to be higher after LS + ED. PVST is a common and potentially life-threatening complication after LS + ED in patients with cirrhosis and PH. Anti-coagulation therapy should be given early, but no standard plan for PSVT prophylaxis has been developed for all patients. In this study, the efficacy and safety of early use of low molecular weight heparin (LMWH) to prevent PVST were retrospectively evaluated compared with conventional anti-coagulant therapy. Of 219 patients with cirrhosis and PH undergoing LS + ED at our hospital from January 2008 to June 2013, 139 received early anti-coagulant therapy with LMWH, and 80 received conventional anti-coagulant therapy. The rates and types of PVST, perioperative coagulation function, intra-abdominal active bleeding, and esophagogastric variceal bleeding (EGVB) were compared in these two groups. Of the 139 patients in the early anti-coagulation group, 42 (30.2 %) experienced postoperative PVST, including two (1.4 %) with main trunk. Of the 80 patients in the conventional anti-coagulation group, 40 (50.0 %) experienced postoperative PVST, including 12 (15.0 %) with main trunk; three (3.8 %) experienced recurrent EGVB due to main trunk thrombosis, and one (1.3 %) underwent an immediate second laparotomy for uncontrollable active bleeding. The rates of postoperative PVST (P = 0.004), main trunk thrombosis (P = 0.000), and EGVB (P = 0.048) were significantly lower in the early than in the conventional anti-coagulant group, but all tested perioperative indices of coagulation function and rates of intraperitoneal active bleeding were similar. Early anti-coagulation with LMWH is safe and effective in patients with LS + ED for cirrhosis and PH.

Portal Vein Thrombosis Is a Risk Factor for Poor Early Outcomes After Liver Transplantation: Analysis of Risk Factors and Outcomes for Portal Vein Thrombosis in Waitlisted Patients

BACKGROUND

Portal vein thrombosis (PVT) is common in patients with cirrhosis, but the risk factors associated with PVT and its impact on outcomes following liver transplantation (LT) are not well defined. The objectives of this study were to determine the impact of PVT on post-LT patient and graft survival, waitlist outcomes, and the factors associated with PVT.

METHODS

A retrospective review of Organ Procurement and Transplant Network waitlist and LT data between 2002 and 2013 identified 48,570 patients undergoing their first LT, with 3321 (6.8%) reported to have PVT at LT.

RESULTS

Portal vein thrombosis was independently associated with increased 90-day mortality (odds ratio, 1.7; 95% confidence interval, 1.45-1.99; P < 0.001) and graft failure (odds ratio, 1.72; 95% confidence interval, 1.51-1.97; P < 0.001). Portal vein thrombosis at listing was not associated with lower transplant rates, or delisting for death, or deterioration. Only 31% of patients with PVT at LT had PVT reported at listing. The predictors of PVT at LT in patients without PVT at listing included: fatty or cryptogenic liver disease, ascites, diabetes mellitus, and obesity. "New" PVT at LT was associated with longer wait-time, higher rate of model of end-stage liver disease increase, and intermediate 90-day survival rates compared to patients with or without PVT at both listing and LT.

CONCLUSIONS

Portal vein thrombosis at LT is associated with early (90 days) mortality and graft failure, though a likely but undefined reporting bias for more extensive PVT would overstate estimated risks for all PVT. Further study is needed to better define risks of LT with PVT.

Coagulopathy in liver disease: Lack of an assessment tool

There is a discrepancy between the information from clotting tests which have routinely been used in clinical practice and evidence regarding thrombotic and bleeding events in patients with liver disease. This discrepancy leads us to rely on other variables which have been shown to be involved in haemostasis in these patients and/or to extrapolate the behaviour of these patients to other settings in order to decide the best clinical approach. The aims of the present review are as follows: (1) to present the information provided by clotting tests in cirrhotic patients; (2) to present the factors that may influence clotting in these patients; (3) to review the clinical evidence; and (4) to put forward a clinical approach based on the first 3 points.

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 high-risk 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 occurring in 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.

Portal vein thrombosis in cirrhosis: Controversies and latest developments

Portal vein thrombosis (PVT) is encountered in liver cirrhosis, particularly in advanced disease. It has been a feared complication of cirrhosis, attributed to significant worsening of liver disease, poorer clinical outcomes and potential inoperability at liver transplantation; also catastrophic events such as acute intestinal ischaemia. Optimal management of PVT has not yet been addressed in any consensus publication. We review current literature on PVT in cirrhosis; its prevalence, pathophysiology, diagnosis, impact on the natural history of cirrhosis and liver transplantation, and management. Studies were identified by a search strategy using MEDLINE and Google Scholar. The incidence of PVT increases with increasing severity of liver disease: less than 1% in well-compensated cirrhosis, 7.4%-16% in advanced cirrhosis. Prevalence in patients undergoing liver transplantation is 5%-16%. PVT frequently regresses instead of uniform thrombus progression. PVT is not associated with increased risk of mortality. Optimal management has not been addressed in any consensus publication. We propose areas for future research to address unresolved clinical questions.

Percutaneous transhepatic balloon-assisted transjugular intrahepatic portosystemic shunt for chronic, totally occluded, portal vein thrombosis with symptomatic portal hypertension: procedure technique, safety, and clinical applications

OBJECTIVES

To introduce a modified transjugular intrahepatic portosystemic shunt (TIPS) procedure, percutaneous transhepatic balloon-assisted TIPS (BA-TIPS), and to evaluate its feasibility and efficacy in patients with chronic totally occluded portal vein thrombosis (CTO-PVT) with symptomatic portal hypertension.

METHODS

Eighteen patients (12 men, six women; mean age 49 years [range, 34-68 years]) with CTO-PVT with symptomatic portal hypertension undergoing BA-TIPS between July 2011 and June 2014 were enrolled in this retrospective study. Rates of technical success, efficacy, and complications were evaluated, and pre- and post-procedure portosystemic gradients compared. Clinical follow-up and periodic assessment of TIPS for patency were performed.

RESULTS

BA-TIPS was successful in fourteen patients and converted to open portosystemic shunt placement in four. Mean portosystemic pressure gradient fell from 24.1 ± 2.3 mmHg to 12.1 ± 3.5 mmHg after BA-TIPS (P < 0.01). No procedure-related complications were observed. During a median follow up of 16 months (range, 3-41 months), there was one death from hepatocellular carcinoma, one death from severe heart disease, and shunt dysfunction 16 months after BA-TIPS in one patient. Shunt patency was maintained in the remaining patients without symptoms of recurrence.

CONCLUSIONS

BA-TIPS is feasible, safe, and effective for CTO-PVT with symptomatic portal hypertension.

KEY POINTS

• Transjugular intrahepatic portosystemic shunt is an important treatment for portal vein thrombosis (PVT). • TIPS is challenging for patients with chronic totally occluded portal vein thrombosis (CTO-PVT). • The use of a balloon increased the technical success of portal puncture. • Balloon-assisted TIPS (BA-TIPS) is feasible, safe, and effective for CTO-PVT.

Portal vein thrombosis

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Extrahepatic portal vein obstruction and portal vein thrombosis in special situations: Need for a new classification

Extrahepatic portal vein obstruction is a vascular disorder of liver, which results in obstruction and cavernomatous transformation of portal vein with or without the involvement of intrahepatic portal vein, splenic vein, or superior mesenteric vein. Portal vein obstruction due to chronic liver disease, neoplasm, or postsurgery is a separate entity and is not the same as extrahepatic portal vein obstruction. Patients with extrahepatic portal vein obstruction are generally young and belong mostly to Asian countries. It is therefore very important to define portal vein thrombosis as acute or chronic from management point of view. Portal vein thrombosis in certain situations such as liver transplant and postsurgical/liver transplant period is an evolving area and needs extensive research. There is a need for a new classification, which includes all areas of the entity. In the current review, the most recent literature of extrahepatic portal vein obstruction is reviewed and summarized.

Portal vein thrombosis in cirrhosis

Portal vein thrombosis (PVT) is being increasingly recognized in patients with advanced cirrhosis and in those undergoing liver transplantation. Reduced flow in the portal vein is probably responsible for clotting in the spleno-porto-mesenteric venous system. There is also increasing evidence that hypercoagulability occurs in advanced liver disease and contributes to the risk of PVT. Ultrasound based studies have reported a prevalence of PVT in 10-25% of cirrhotic patients without hepatocellular carcinoma. Partial thrombosis of the portal vein is more common and may not have pathophysiological consequences. However, there is high risk of progression of partial PVT to complete PVT that may cause exacerbation of portal hypertension and progression of liver insufficiency. It is thus, essential to accurately diagnose and stage PVT in patients waiting for transplantation and consider anticoagulation therapy. Therapy with low molecular weight heparin and vitamin K antagonists has been shown to achieve complete and partial recanalization in 33-45% and 15-35% of cases respectively. There are however, no guidelines to help determine the dose and therapeutic efficacy of anticoagulation in patients with cirrhosis. Anticoagulation therapy related bleeding is the most feared complication but it appears that the risk of variceal bleeding is more likely to be dependent on portal pressure rather than solely related to coagulation status. TIPS has also been reported to restore patency of the portal vein. Patients with complete PVT currently do not form an absolute contraindication for liver transplantation. Thrombectomy or thromboendovenectomy is possible in more than 75% of patients followed by anatomical end-to-end portal anastomosis. When patency of the portal vein and/or superior mesenteric vein is not achieved, only non-anatomical techniques (reno-portal anastomosis or cavo-portal hemitransposition) can be performed. These techniques, which do not fully reverse portal hypertension, are associated with higher morbidity and mortality risks in the short term.