Current management of portal vein thrombosis in liver transplantation

Unique multidisciplinary approach in living donor liver transplantation to achieve total physiological revascularization in a patient with complete occlusion of portal vein system with combined chronic and subacute thrombosis

Patients receiving liver transplantation in a setting of complete portal vein (PV) and superior mesenteric vein (SMV) thrombosis (Yerdel grade 4) experience lower outcomes after surgery; prognosis is independently influenced by the portal flow reconstruction technique, showing better outcomes in physiological surgical strategies. We describe a case of living donor liver transplantation in which the patient could not receive common physiological reconstructions preoperatively due to multiple small collaterals and extensive thrombosis down to first branches of SMV. We performed thromboendovenectomy of the PV and SMV first, but acute thrombosis developed recurrently even with interposition venous homograft between pericholedochal collateral vein and proximal recipient PV. Immediate after surgery, an intervention radiologist performed stent insertion into 3 stenotic points. Through multidisciplinary approach, complete physiological recanalization was obtained with normal liver function.

A Novel Preoperative Classification System for Selecting Suitable Surgeries in Liver Transplant Patients with Portal Vein Cavernous Transformation

BACKGROUND

To evaluate the new preoperative Changgung classification (CC) system of portal vein thrombosis (PVT) in choosing suitable operative procedures to reconstruct portal veins during liver transplantation (LT) in patients with portal vein cavernous transformation (PVCT).

METHODS

This retrospective observational study analyzed data from allograft LTs performed for various liver diseases.

RESULTS

The study included 22 males and 4 females with LT indications comprising cirrhosis (n = 9), hepatocellular carcinoma (n = 12), PVCT (n = 2), liver failure from fulminant hepatitis B (n = 1), dysfunction of transplanted liver (n = 1), and chronic rejection of transplanted liver (n = 1). Patients were classified according to Yerdel (21 Yerdel II and 5 Yerdel III) and CC (C1-C5). In total 16 simple operations were performed on C1-C3 cases and 9 complex operations on C4-C5 cases, with one additional simple operation. The distribution according to the Yerdel classification was 16 simple and 5 complex operations in Yerdel II cases and 1 simple and 4 complex operations in Yerdel III cases. The median follow-up time was 27.5 months with overall one-year and three-year OS rates of 88.1% and 83.9% for the cohort. Specifically, the one-year OS rates for patients classified as C1-3 vs. C4-5 were 93.3% and 80.0%, while the three-year OS rates were 86.7% and 80.0%, respectively (p = 0.526).

CONCLUSION

The CC proposed in this study shows comparable potential to the Yerdel classification in preoperatively identifying the need for complex surgical techniques in LT patients with PVCT and may also have predictive power for the survival benefits following LT.

Portal vein thrombosis and liver transplantation: management, matching, and outcomes. A retrospective multicenter cohort study

BACKGROUND AND AIMS

Besides the increased risk of perioperative morbidity, graft failure, and mortality, the majority of PVT are diagnosed at liver transplantation (LT). Improving preoperative management and patient selection may lead to better short-term and long-term outcomes and reduce the risk of a futile LT. The authors aimed to identify predictors of adverse outcomes after LT in patients with nonmalignant portal vein thrombosis (PVT) and improve donor to recipient matching by analyzing the results of the Italian cohort of LT recipients.

METHODS

Adult patients who underwent LT in Italy between January 2000 and February 2020 diagnosed with PVT pre-LT or at time of LT were considered eligible for inclusion. Based on a survey encompassing all 26 surgeons participating in the study, a binary composite outcome was defined. Patients were classified as having the composite event if at least one of these conditions occurred: operative time more than 600 min, estimated blood loss greater than 5000 ml, more than 20 ICU days, 90 days mortality, 90 days retransplant.

RESULTS

Seven hundred fourteen patients were screened and 698 met the inclusion criteria. The analysis reports the results of 568 patients that fulfilled the criteria to enter the composite outcome analysis.Overall, 156 patients (27.5%) developed the composite outcome. PVT stage 3/4 at transplant and need for any surgical correction of PVT are independent predictors of the composite outcome occurrence. When stratified by PVT grade, overall survival at 1-year ranges from 89.0% with PVT grade 0/1 to 67.4% in patients with PVT grade 3/4 at LT ( P <0.001). Nevertheless, patients with severe PVT can improve their survival when identified risk factors are not present.

CONCLUSIONS

Potential LT candidates affected by PVT have a benefit from LT that should be adequately balanced on liver function and type of inflow reconstruction needed to mitigate the incidence of adverse events. Nonetheless, the absence of specific risk factors may improve the outcomes even in patients with PVT grades 3-4.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Global research on portal vein thrombosis and liver transplantation: A bibliometric and visualized study

In recent years, the association between portal vein thrombosis and liver transplantation has extensive attention from physicians worldwide. However, there is no available literature on bibliometric analysis in this research area. Herein, we aimed to conduct a bibliometric analysis to identify the hotspots and frontiers of research related to portal vein thrombosis and liver transplantation. Documents published between 2002 and 2022 were retrieved and downloaded from the Web of Science Core Collection database. VOSviewer was utilized to generate a visualization network map of authors, nations, institutions, journals, and keyword co-occurrence/clustering. Additionaly, CiteSpace was used to analyze the keywords with the strongest bursts. A total of 1272 articles and reviews were extracted from the database. The author Marco Senzolo published the largest number of papers. The United States was the most prolific country, and Hope-Bochon (France) was the top productive institution. Liver Transplantation was the most prolific journal in the field. The most commonly identified keywords in the study were cirrhosis, risk factors, portal vein thrombosis, and management, as revealed by the keyword co-occurrence analysis. It is suggested that patients with cirrhosis, portal vein thrombosis prevention, and management measures for portal vein thrombosis have been prominet topics in recent years. Furthermore, an analysis of keywords with the strongest citation bursts highlighted pediatric liver transplantation, direct oral anticoagulants, and nonalcoholic fatty liver disease as current research trends. Research in portal vein thrombosis and liver transplantation exhibits a general upward trend. The latest hot topics within this area of study involve pediatric patients and nonalcoholic fatty liver disease.

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 thrombosis in liver cirrhosis: An updated overview

Portal vein thrombosis (PVT) is a frequent and severe complication in patients with cirrhosis; however, the pathophysiology of PVT needs to be better clarified. There are few significant predictive factors in clinical practice, and the impact of PVT on cirrhosis progression and its complications, such as gastrointestinal bleeding, hepatic encephalopathy, and hepatorenal syndrome, remains uncertain. In recent years, the understanding of the mechanisms of PVT has become more profound with the publication of related literature. Therefore, in this review, we aim to summarize the advanced progress in the epidemiology, hazards, risk factors, diagnosis and classification, and treatment of PVT to provide insight into clinical management.

Recurrent Portal Vein Thrombosis In Liver Transplantation With Renoportal Anastomosis Caused by Spontaneous Reno-Caval Shunts: A Case Report

BACKGROUND

Orthotopic liver transplantation (OLT) in patients with cirrhosis complicated by portal hypertension, portosystemic shunts, and chronic portal vein thrombosis (PVT) has long been challenging. Spontaneous spleno-renal shunts (SRS) allow new surgical techniques to restore portal vein patency and hepatopetal flow. Renoportal anastomosis (RPA) has emerged as an accepted method for transplanting these patients, with good long-term patient and graft survival. Orthotopic liver transplantation with RPA is known to be complicated by recurrent PVT, with few details discussed in the literature.

CASE REPORT

We present a case of a 56-year-old woman with decompensated cirrhosis who underwent deceased donor whole graft OLT using RPA with iliac vein conduit. The postoperative course was complicated by occlusive thrombosis in the portal vein and iliac vein conduit. Venography revealed enlarged left gonadal and lumbar vein varices acting as reno-caval shunts with hepatofugal flow. Embolization of the varices re-established durable venous patency that was confirmed on post-transplant day 68 with no other hemodynamic complications.

DISCUSSION

This showcases an interesting mechanism by which recurrent PVT may occur in patients undergoing OLT with RPA. Because durable portal vein patency can be achieved with Interventional Radiology embolization of reno-caval varices, assessing these communications is an important preoperative consideration for planned OLT with RPA.

Portal Vein Pull-Through Technique and Thrombectomy for Extensive Portal Vein Thrombosis

BACKGROUND

Herein, a different technique is presented describing complete dissection of the entire portal vein (PV), superior mesenteric vein (SMV), and splenic vein, thus enabling a complete thrombectomy without the risk of uncontrolled hemorrhage due to blind thrombectomy.

METHODS

In cases where a thrombectomy would not be an option because of extensive thrombosis involving the confluence of the PV and SMV, small branches of the SMV, including the inferior mesenteric vein, were divided. Both the SMV and splenic vein were encircled separately. Then, the side branches of the PV above the pancreas, left gastric vein on the left side, and superior pancreatoduodenal vein on the right side were divided. The lateral and posterior part of the PV were dissected within the pancreas both from above and below, allowing the main PV completely free from attachments. At this point, the splenic vein and SMV were clamped, and the main PV was divided above the pancreas and then pulled back through the pancreatic tunnel. The thrombus was easily dissected of the vein under direct visualization, and afterward the PV was redirected to its original position. Then, the liver transplant was carried out in a regular fashion.

RESULTS

This technique was applied to 2 patients. The first was a 43-year-old man who underwent a right lobe living donor liver transplant because of hepatitis B virus-related cirrhosis. The patient is still alive and well with stable liver function after 15 years of follow-up. The second was a 69-year-old woman who underwent a right lobe living donor liver transplant because of hepatitis C virus and hepatocellular carcinoma. She survived the procedure and her liver function was entirely normal afterward. She died of pneumonia and sepsis 5 months after transplant.

CONCLUSIONS

This technique enables complete dissection of the entire PV, SMV, and splenic vein. Thus, complete thrombectomy under direct visualization without the risk of uncontrolled hemorrhage can be performed.

Liver transplantation for cirrhosis complicated by non-tumor thrombosis of mesenteric portal system

Aim. To develop a universal technology of thrombectomy from the veins of the mesenteric portal system and to evaluate the outcomes of liver transplantation for cirrhosis combined with non-tumorous portal vein thrombosis.Materials and methods. Immediate and long-term results of 309 transplantations in patients with liver cirrhosis of various etiologies were studied. In 46 cases (14.9%), transplantation was performed in patients with liver cirrhosis and concomitant thrombosis in the veins of the mesenteric portal system. Results. A versatile method of thrombectomy, depending on the degree of thrombosis in the veins of the mesenteric portal system was proposed (M.A. Yerdel et al., 2000). Mesenteric portal vein thrombosis increased duration of transplantation and volume of intraoperative blood loss as compared to patients without concomitant thrombosis. No statistically significant differences were found in the overall incidence of postoperative complications, hospital mortality and duration of hospitalization of the patients after liver transplantation with concomitant venous thrombosis compared to the patients without thrombosis. The incidence of thrombotic complications, including hepatic artery thrombosis, was significantly higher after liver transplantation supplemented with thrombectomy from the portal vein system. Five-year survival rate of the patients after liver transplantation with concomitant thrombosis in the veins of the mesenteric portal system was 94.9% (median – 40 months), patients without thrombosis in the veins of the mesenteric portal system – 93.2% (median – 60 months).Conclusion. Transplantation in patients with cirrhosis and thrombosis in the veins of the mesenteric-portal system shows good immediate and long-term results in case proper thrombectomy is carried out.

Portal vein-variceal anastomosis for portal vein inflow reconstruction in orthotopic liver transplantation: A case report and review of literature

BACKGROUND

Portal vein thrombosis (PVT) is a frequent complication occurring in 5% to 26% of cirrhotic patients candidates for liver transplantation (LT). In cases of extensive portal and or mesenteric vein thrombosis, complex vascular reconstruction of the portal inflow may become necessary for a successful orthotopic LT (OLT).

CASE SUMMARY

A 54-year-old male with history of cirrhosis secondary to schistosomiasis complicated with extensive portal and mesenteric vein thrombosis and severe portal hypertension who underwent OLT with portal vein-left gastric vein anastomosis.

CONCLUSION

We review the various types of PVT, the portal venous inflow reconstruction techniques.

LncRNA Snhg1 Plays an Important Role via Sequestering rno-miR-139-5p to Function as a ceRNA in Acute Rejection After Rat Liver Transplantation Based on the Bioinformatics Analysis

In order to explore the molecular mechanism of acute rejection after liver transplantation (ARLT) in rats, we employed the GSE36798 data set in the Gene Expression Omnibust (GEO) database to construct a related ceRNA network. This dataset contained a total of 16 samples (8 graft samples and 8 plasma samples). Each kind of sample was divided into acute rejection (AR) groups and non-acute rejection (NR) groups, and each group had 4 replicates. First, we performed principal component analysis (PCA) with downloaded data to compare the difference between samples in a macroscopic way. Then, we used the “limma” R package to screen out differentially expressed miRNAs among different groups and used the “pheatmap” R package to perform bidirectional hierarchical clustering analysis for these differentially expressed miRNAs. The miRWalk database and the LncBase V.2 database were applied to predict downstream target genes and upstream-related lncRNAs, respectively. Meanwhile, the String database was used to predict the relationship between target genes, and the aforementioned results were processed for visualization by Cytoscape software. In addition, we exhibited the ultimate ceRNA network, including two lncRNAs, two miRNAs, and 77 mRNAs. Finally, we constructed a rat model of ARLT and applied graft specimens to relevant experimental verification. We found that the lncRNA Snhg1/rno-miR-139-5p axis might be involved in the regulation of ARLT in rats. In short, we demonstrated the differentially expressed miRNA profile, constructed a related ceRNA network, and screened out a possible regulatory axis. In view of the conservation of genes among species, this work was expected to provide a new strategy for the treatment and prevention of ARLT in the clinical setting.

Direct oral anticoagulant administration in cirrhotic patients with portal vein thrombosis: What is the evidence?

In recent years, the traditional concept that cirrhosis-related coagulopathy is an acquired bleeding disorder has evolved. Currently, it is known that in cirrhotic patients, the hemostatic system is rebalanced, which involves coagulation factors, fibrinolysis and platelets. These alterations disrupt homeostasis, skewing it toward a procoagulant state, which can lead to thromboembolic manifestations, especially when hemodynamic and endothelial factors co-occur, such as in the portal vein system in cirrhosis. Portal vein thrombosis is a common complication of advanced liver cirrhosis that negatively affects the course of liver disease, prognosis of cirrhotic patients and success of liver transplantation. It is still debated whether portal vein thrombosis is the cause or the consequence of worsening liver function. Anticoagulant therapy is the mainstay treatment for acute symptomatic portal vein thrombosis. In chronic portal vein thrombosis, the role of anticoagulant therapy is still unclear. Traditional anticoagulants, vitamin K antagonists and low-molecular-weight heparin are standard-of-care treatments for portal vein thrombosis. In the last ten years, direct oral anticoagulants have been approved for the prophylaxis and treatment of many thromboembolic-related diseases, but evidence on their use in cirrhotic patients is very limited. The aim of this review was to summarize the evidence about the safety and effectiveness of direct oral anticoagulants for treating portal vein thrombosis in cirrhotic patients.

Physiological reno-portal bypass in liver transplantation with non-tumorous portal vein thrombosis

Reno-portal anastomosis (RPA) in presence of spleno-renal shunts (SRS) is a physiological option to restore blood flow in liver transplantation with portal vein thrombosis (PVT). Diffuse splanchnic venous system thrombosis (complex PVT) is its main indication but RPA proved to be useful in selected cases of less extensive thrombosis (non-complex PVT). Up until now only two monocentric and one multicentric case series has been published on this topic in addition to few anecdotal reports. After 2014, we introduced RPA in our institution to manage some cases of complex PVT in presence of SRS. Here, we present the evolution of indication to RPA. From 2014 to 2020, we performed ten RPA: nine patients presented non-complex and one complex PVT. Overall early and late complication rates were 66.6% and 50%, respectively. Two patients developed RPA stenosis, treated by interventional radiology. Self-resolving acute kidney injury (AKI) was observed in three cases. No re-transplantation was necessary. RPA was patent in all patients, with a mean follow-up of 41.9 months. The overall patient survival was 70% at 1 year and 60% at 3 and 5 years. Four patients died at 1, 2, 3 and 20 months from LT. Causes of deaths were, respectively, stroke, cerebral infection, sepsis (MOF) and sudden variceal bleeding in sinusoidal obstruction syndrome. The relative simplicity and effectiveness of RPA in presence of SRS allowed us to rely more and more often on this technique in liver transplantation with challenging non-complex PVT.

Nontransplant options for portomesenteric thrombosis

PURPOSE OF REVIEW

Portomesenteric thrombosis (PMT) is a serious condition encountered mainly in cirrhotic patients awaiting liver transplantation. More recently, this potentially fatal complication has been described after bariatric surgery and inflammatory bowel disease. Several consensus guidelines have been published over the past few years and this mini review was conducted to discuss updated nontransplant treatment options based on currently available evidence.

RECENT FINDINGS

Anticoagulation is the mainstay of treatment for PMT involving <50% of the main portal vein. Transjugular intrahepatic portosystemic shunt are usually preserved for patients with more extensive disease or those with clinically significant portal hypertension that are treatment refractory.

SUMMARY

The extent of PMT, response to therapy, and complications related with PMT are the determinants of therapy.

The Pathophysiology of Portal Vein Thrombosis in Cirrhosis: Getting Deeper into Virchow's Triad

Portal vein thrombosis (PVT) is a common complication among patients with cirrhosis. However, its pathophysiology is not well established and there are currently very few predictive factors, none of which are actually useful, from a clinical perspective. The contribution of each of the vertices of Virchow’s triad, e.g., blood hypercoagulability, blood flow, and portal vein endothelial damage in the development of PVT is not clear. In this review, we aim to recapitulate the latest studies on the field of PVT development in order to understand its mechanisms and discuss some of the future directions in the study of this important complication of cirrhosis.

Recommendations for Donor and Recipient Selection and Risk Prediction: Working Group Report From the ILTS Consensus Conference in DCD Liver Transplantation

Although the utilization of donation after circulatory death donors (DCDs) for liver transplantation (LT) has increased steadily, much controversy remains, and no common acceptance criteria exist with regard to donor and recipient risk factors and prediction models. A consensus conference was organized by International Liver Transplantation Society on January 31, 2020, in Venice, Italy, to review the current clinical practice worldwide regarding DCD-LT and to develop internationally accepted guidelines. The format of the conference was based on the grade system. International experts in this field were allocated to 6 working groups and prepared evidence-based recommendations to answer-specific questions considering the currently available literature. Working group members and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and recommendations provided by working group 2, covering the entire spectrum of donor and recipient risk factors and prediction models in DCD-LT.

Nontumoral Portal Vein Thrombosis: A Challenging Consequence of Liver Cirrhosis

Nontumoral portal vein thrombosis (PVT) is an increasingly recognized complication in patients with cirrhosis. Substantial evidence shows that portal flow stasis, complex thrombophilic disorders, and exogenous factors leading to endothelial dysfunction have emerged as key factors in the pathogenesis of PVT. The contribution of PVT to hepatic decompensation and mortality in cirrhosis is debatable; however, the presence of an advanced PVT increases operative complexity and decreases survival after transplantation. The therapeutic decision for PVT is often determined by the duration and extent of thrombosis, the presence of symptoms, and liver transplant eligibility. Evidence from several cohorts has demonstrated that anticoagulation treatment with vitamin K antagonist or low molecular weight heparin can achieve recanalization of the portal vein, which is associated with a reduction in portal hypertension-related events and improved survival in cirrhotic patients with PVT. Consequently, interest in direct oral anticoagulants for PVT is increasing, but clinical data in cirrhosis are limited. Although the most feared consequence of anticoagulation is bleeding, most studies indicate that anticoagulation therapy for PVT in cirrhosis appears relatively safe. Interestingly, the data showed that transjugular intrahepatic portosystemic shunt represents an effective adjunctive therapy for PVT in cirrhotic patients with symptomatic portal hypertension if anticoagulation is ineffective. Insufficient evidence regarding the optimal timing, modality, and duration of therapy makes nontumoral PVT a challenging consequence of cirrhosis. In this review, we summarize the current literature and provide a potential algorithm for the management of PVT in patients with cirrhosis.