Autoimmune conditions are associated with perioperative thrombotic complications in liver transplant recipients: A UNOS database analysis

The etiology of chronic splanchnic vein thrombosis in adults: a two-center analysis

Portal vein thrombosis (PVT) and Budd-Chiari syndrome (BCS) are rare vascular disorders with both well-recognized and less commonly identified etiologies.

OBJECTIVES

This study aims to investigate the etiologies of portal vein thrombosis (PVT) and Budd-Chiari syndrome (BCS), thereby enhancing improving early detection and management strategies for these conditions. A retrospective review was undertaken to identify the etiologies of PVT and BCS.

METHODS

A detailed clinical evaluation was performed and all underlying diseases, such as MPD, and related conditions (e.g. surgery) associated with thrombosis were recorded.

RESULTS

The study comprised a total of 73 patients, with 58 diagnosed with PVT and 15 with BCS. Of these patients, 56 (76.7%) had at least one underlying disease. The most prevalent underlying diseases in patients with PVT were cirrhosis (32/58, 55.2%), myeloproliferative disease (3/58, 5.2%), malignancy (4/58, 6.9%), and rheumatological conditions (4/58, 6.9%). For BCS, 11/15 patients (73.3%) had at least one predisposing condition, including cirrhosis in six cases. Congenital causes were identified in 16/58 cases of PVT (27.6%), in 7/15 cases of BCS (46.7%). Thirty-two patients had previously undergone gastrointestinal surgery (PVT 24/58, BCS 8/15); surgery was the sole etiology in 15/73 patients (20.5%). Homocysteinemia was common (PVT 20/58, BCS 5/15). A multitude of rare etiologies were identified, including paroxysmal nocturnal haemoglobinuria, Crohn's disease, nephrotic syndrome, drug therapies, pregnancy, JAK2 mutation, and elevated factor VIII or fibrinogen.

CONCLUSIONS

The presence of a wide range of diverse frequent-infrequent etiologies of congenital or acquired splanchnic vein thrombosis in this cohort underscores the necessity for the implementation of appropriate diagnostic strategies in a broad spectrum of at-risk patients.

Regulatory T cells-related gene in primary sclerosing cholangitis: evidence from Mendelian randomization and transcriptome data

The present study utilized large-scale genome-wide association studies (GWAS) summary data (731 immune cell subtypes and three primary sclerosing cholangitis (PSC) GWAS datasets), meta-analysis, and two PSC transcriptome data to elucidate the pivotal role of Tregs proportion imbalance in the occurrence of PSC. Then, we employed weighted gene co-expression network analysis (WGCNA), differential analysis, and 107 combinations of 12 machine-learning algorithms to construct and validate an artificial intelligence-derived diagnostic model (Tregs classifier) according to the average area under curve (AUC) (0.959) in two cohorts. Quantitative real-time polymerase chain reaction (qRT-PCR) verified that compared to control, Akap10, Basp1, Dennd3, Plxnc1, and Tmco3 were significantly up-regulated in the PSC mice model yet the expression level of Klf13, and Scap was significantly lower. Furthermore, immune cell infiltration and functional enrichment analysis revealed significant associations of the hub Tregs-related gene with M2 macrophage, neutrophils, megakaryocyte-erythroid progenitor (MEP), natural killer T cell (NKT), and enrichment scores of the autophagic cell death, complement and coagulation cascades, metabolic disturbance, Fc gamma R-mediated phagocytosis, mitochondrial dysfunction, potentially mediating PSC onset. XGBoost algorithm and SHapley Additive exPlanations (SHAP) identified AKAP10 and KLF13 as optimal genes, which may be an important target for PSC.

Surgical strategies to treat portal vein thrombosis during adult liver transplantation

BACKGROUND

The incidence of portal vein thrombosis (PVT) at the time of liver transplantation (LT) may be variable and underestimated. Therefore, preoperative diagnosis and stratification of its extension is so relevant for adequate surgical planning. Revascularization of the portal vein graft becomes essential for graft and patient survival after LT. Early stages of PVT may be managed with eversion thrombectomy and end-to-end anastomoses. However, severe PVT (grades 3 and 4) poses significant challenges for patients requiring LT, resulting in more complex surgeries and higher complication rates. To address these complexities, various surgical techniques have been developed, including collateral alternative vessel utilization, renoportal anastomoses, mesoportal jump graft placement, cavoportal hemitranspositions, portal vein arterialization, or even multivisceral transplantation.

PURPOSE

We herein describe the preoperative surgical planning as well as the different surgical strategies possible to treat portal vein thrombosis during LT.

CONCLUSION

A comprehensive preoperative evaluation of PVT is crucial for accurately assessing its extent and severity. This information is vital for proper surgical planning, which ultimately prepares both the surgeon and the patient for potentially complex procedures during LT. The surgical alternatives presented in this technical report offer promising solutions for treating PVT during LT, making it a viable option for selected patients.

The Yin and the Yang of Hemostasis in End-Stage Liver Disease

Patients with end-stage liver disease (ESLD) undergoing liver transplantation (LT) are prone to thromboses both while on the waiting list and in the perioperative period. This hypercoagulability is associated with significant endothelial dysfunction (ED) due to nitric oxide dysregulation. ED and increased thrombin generation are the main factors responsible for this hypercoagulability. Sepsis alone can significantly alter a patient's coagulation profile. In combination with ESLD, however, sepsis or septic shock are responsible for very complex changes. This makes both the assessment and management of coagulation in septic patients with ESLD very challenging. Viscoelastic testing (VET) is the preferred method of coagulation management in patients with cirrhosis because, as with standard laboratory testing, VET can assess the entire coagulation system including the interaction between both pro- and anticoagulants and platelets.

Autoimmune diseases and orthognathic surgery: A case series of 12 patients

Autoimmune diseases result from the immune system attacking native cells and tissues due to the recognition of "self" antigens as foreign antigens. This group of disorders is associated with an increased risk of complications after surgical interventions, as the immune system may cause tissue destruction. The study aimed to investigate the risk of surgical complications in patients with autoimmune diseases, who are at a higher risk of complications due to their condition. Among 886 patients who underwent orthognathic surgery, twelve types of autoimmune diseases with 22 patients were identified. For this case-series study, 12 patients were selected with a follow-up period of at least two years. The surgical procedures were executed by a single surgical team, which involved single or multi-piece Le Fort I osteotomy, Hunsuck/Epker modification of bilateral sagittal split osteotomy (BSSO), and/or genioplasty. The recorded outcome variables were postoperative adverse events, including respiratory or blood-related complications, wound infection, neurosensory disturbances, temporomandibular joint (TMJ) complications, and relapse. Only two patients recovered after surgery without any postoperative complications, whereas others had delayed recovery from neurosensory disturbance (5/12), infection (5/12), TMJ complications (2/12), and other complications. The findings of this study suggest that patients with autoimmune diseases undergoing orthognathic surgery are at higher risk of complications, highlighting the importance of careful consideration of patient selection and risk stratification before surgical intervention. The study also emphasizes the importance of close postoperative follow-up to detect and manage complications promptly.

Liver transplantation for autoimmune hepatitis: Pre-transplant does not predict the early post-transplant outcome

BACKGROUND AND AIMS

Autoimmune hepatitis (AIH) is a rare indication (<5%) for liver transplantation (LT). The aim of this study was to describe the early outcome after LT for AIH.

METHODS

A multicenter retrospective nationwide study including all patients aged ≥16 transplanted for AIH in France was conducted. Occurrences of biliary and vascular complications, rejection, sepsis, retransplantation and death were collected during the first year after LT.

RESULTS

A total of 344 patients (78.8% of women, 17.0% of (sub)fulminant hepatitis and 19.2% of chronic liver diseases transplanted in the context of acute-on-chronic liver failure [ACLF]) were included, with a median age at LT of 43.6 years. Acute rejection, sepsis, biliary and vascular complications occurred in respectively 23.5%, 44.2%, 25.3% and 17.4% of patients during the first year after LT. One-year graft and patient survivals were 84.3% and 88.0% respectively. The main cause of early death was sepsis. Pre-LT immunosuppression was not associated with an increased risk for early infections or surgical complications. Significant risk factors for septic events were LT in the context of (sub)fulminant hepatitis or ACLF, acute kidney injury at the time of LT (AKI) and occurrence of biliary complications after LT. AKI was the only independent factor associated with graft (HR = 2.5; 95% CI: 1.1-5.4; p = .02) and patient survivals (HR = 2.6; 95% CI: 1.0-6.5; p = .04).

CONCLUSION

Early prognosis is good after LT for AIH and is not impacted by pre-LT immunosuppression but by the presence of AKI at the time of LT.

The importance of liver function assessment before cardiac surgery: A narrative review

The demand for cardiac surgery procedures is increasing globally. Thanks to an improvement in survival driven by medical advances, patients with liver disease undergo cardiac surgery more often. Liver disease is associated with the development of heart failure, especially in patients with advanced cirrhosis. Cardiovascular risk factors can also contribute to the development of both cardiomyopathy and liver disease and heart failure itself can worsen liver function. Despite the risk that liver disease and cirrhosis represent for the perioperative management of patients who undergo cardiac surgery, liver function is often not included in common risk scores for preoperative evaluation. These patients have worse short and long-term survival when compared with other cardiac surgery populations. Preoperative evaluation of liver function, postoperative management and close postoperative follow-up are crucial for avoiding complications and improving results. In the present narrative review, we discuss the pathophysiological components related with postoperative complications and mortality in patients with liver disease who undergo cardiac surgery and provide recommendations for the perioperative management.

Incident portal vein thrombosis in liver transplant recipients in New Zealand: Predictors of risk and validation of portal vein thrombosis risk index calculator

The risk of spontaneous portal vein thrombosis (PVT) is increased in patients on the waiting list for liver transplantation and increases perioperative risks. A predictive PVT risk-index (PVT-RI) calculator has been proposed to determine the risk of incident PVT. We performed a retrospective analysis on adult liver transplant recipients at the NZ Liver Transplant Unit between January 1998 and February 2020. Variables reviewed included age at listing and transplantation, wait time from listing to transplant, indication for listing, gender, ethnicity, etiology of liver disease, listing MELD score, hepatocellular carcinoma (HCC), moderate-to-severe ascites, hepatic encephalopathy (>grade 2), transjugular intrahepatic portosystemic shunt (TIPSS), spontaneous bacterial peritonitis (SBP), and diabetes. Incident PVT was determined by imaging of patients while on the waiting list and assessment at transplantation. A total of 553 out of 706 patients met the inclusion criteria. Of those 553, 18 (3.3%) patients had incident PVT. The PVT-RI calculator was not validated in our cohort with only one of those 18 (6%) patients having a score of >4.6 (high risk cut-off score). Longer waiting time for transplant and listing for liver failure rather than HCC were independent predictors of the risk of incident PVT. There was no statistically significant difference in the incidence of PVT in viral vs. non-viral and cholestatic vs. non-cholestatic etiology of chronic liver disease. Patients with longer waiting times on the transplant waiting list should be monitored regularly for PVT.

Prevalence of bleeding and thrombosis in critically ill patients with chronic liver disease

INTRODUCTION

Haemorrhage and venous thromboembolism (VTE) are recognised complications of chronic liver disease (CLD), but their prevalence and risk factors in critically ill patients is uncertain.

PATIENTS AND METHODS

We studied a retrospective cohort of patients with CLD non-electively admitted to a specialist intensive care unit determining the prevalence and timing of major bleeding and VTE (early, present on admission/diagnosed within 48h; later diagnosed >48h post ICU admission). Associations with baseline clinical and laboratory characteristics, multi-organ failure (MOF), blood product administration and mortality were explored. Odds ratios (OR) and 95% CIs were calculated using logistic regression.

RESULTS

Of 623 patients with median age 52, bleeding (>48 hours after admission) occurred in 87 (14%) patients. Bleeding was associated with greater illness severity and increased mortality. Gastrointestinal bleeding accounted for 72% of events, secondary to portal hypertension in >90%. Procedure-related bleeding was uncommon. VTE occurred in 125 (20%) patients: Early VTE in 80 (13%) and involving the portal vein (PVT) in 85%. Later VTE affected 45 (7.2%) patients. Hepatocellular Carcinoma (HCC) and non-alcoholic liver disease were independently associated with early VTE (OR 2.79, (95% CI 1.5 -5.2) and 2.32, (1.4 -3.9) respectively), and HCC, sepsis and cryoprecipitate use with late VTE (OR 2.45, (1.11-5.43), 2.26 (1.2-4.3) and 2.60 (1.3-5.1).

CONCLUSION

VTE was prevalent on admission to critical care and less commonly developed later. Bleeding was associated with MOF and increased mortality. Severe MOF was not associated with an increased rate of VTE which was linked with HCC, and specific etiologies of CLD.

Portal vein thrombosis prevalence and mortality among alcoholic cirrhosis in a nationwide inpatient cohort

OBJECTIVES

Portal vein thrombosis is commonly associated with cirrhosis. The effect of alcoholic cirrhosis on portal vein thrombosis prevalence and mortality has not been well studied.

METHODS

We conducted a retrospective cohort study utilizing the 2000-2014 National Inpatient Sample Database. We included patients older than 18 years with decompensated cirrhosis without a history of liver transplantation or hepatocellular carcinoma. We further identified patients with alcoholic cirrhosis vs. non-alcoholic cirrhosis. Primary outcomes included the risk and mortality of portal vein thrombosis in alcoholic cirrhosis. Secondary outcomes included trends of portal vein thrombosis prevalence and mortality in alcoholic cirrhosis, implications of portal vein thrombosis on complications in alcoholic cirrhosis vs. non-alcoholic cirrhosis, and risk of venous thromboembolism in alcoholic cirrhosis.

RESULTS

Among 1 892 271 patients with decompensated alcoholic cirrhosis, portal vein thrombosis prevalence was 1.3%. Alcoholic cirrhosis was associated with lower risk of portal vein thrombosis (odds ratio 0.76, P < 0.001) and venous thromboembolism (odds ratio 0.69, P < 0.001) compared to non-alcoholic cirrhosis. Portal vein thrombosis contributed to increased mortality (odds ratio 1.19, P < 0.001) in alcoholic cirrhosis. Portal vein thrombosis prevalence among alcoholic cirrhosis increased while mortality declined during the study period.

CONCLUSION

Thrombotic events including portal vein thrombosis and venous thromboembolism were found in less frequent association with alcoholic cirrhosis compared with non-alcoholic cirrhosis. Despite this, the higher in-hospital mortality found among portal vein thrombosis with alcoholic cirrhosis should prompt careful consideration of management.

Incidence of Bleeding and Thrombosis in Patients with Liver Disease

Historically, liver disease has been associated with a bleeding tendency. Global hemostatic assays have demonstrated that hemostasis is overall rebalanced, in both acute liver failure and chronic liver disease. It is now recognized that many bleeding events in chronic liver disease are mediated by portal hypertension rather than an underlying hemostatic defect. This is acknowledged in recent guidelines, which recommend against coagulation testing prior to low risk procedures in this patient group, with avoidance also of attempts at correction of prolonged coagulation times. Over time, the incidence of bleeding events has decreased in both chronic liver disease and acute liver failure, with improved supportive care, targeted treatments for underlying cause of liver disease, and the advent of liver transplantation. Concurrently, there has been increased recognition of the risk of thrombosis in chronic liver disease, with a predilection for the splanchnic vasculature. This review describes the incidence of bleeding and thrombosis in chronic liver disease and acute liver failure, including the periprocedural and liver transplantation setting.

Outcome for Pediatric Recipients of Macrosteatotic Liver Grafts From Living Donors

In deceased donor liver transplantation, a donor liver with moderate (>30%) macrosteatosis used to be considered inappropriate for grafting. We examined the outcomes of children who underwent living donor liver transplantation (LDLT) at the National Center for Child Health and Development whose donor livers had moderate-to-severe macrosteatosis. Twelve children were enrolled who had received a moderate-to-severe macrosteatotic liver graft and underwent liver biopsy soon after LDLT. The primary diseases were biliary atresia in 7 patients, acute liver failure in 3 patients, glycogen storage disease type 1 in 1 patient, and primary sclerosing cholangitis in 1 patient. Median age was 11 months. There were 4 recipients who received grafts from their fathers, and 8 received grafts from their mothers. Median donor age was 35.5 years. We compared the degree of donor liver steatosis with the results of graft liver biopsies that were collected 4-105 days after LDLT. The levels of donor liver macrovesicular steatosis were moderate (34%-66%) in 9 patients and severe (>66%) in 3 patients. The nonalcoholic fatty liver disease activity score was 3 in 7 patients and 4 in 5 patients. Shortly after LDLT, 11 of 12 patients showed improvement in steatosis compared with the donor livers. One biopsy specimen taken 22 days after LDLT showed 60% macrosteatosis, which was the same as that in the donor liver. However, this patient was alive and well 6 years after LDLT. One patient died after LDLT because of infection and respiratory failure. The levels of steatosis of the donor liver grafts improved soon after LDLT in children, and the outcomes of children receiving a moderate-to-severe macrosteatotic liver from their parents were excellent.

Comparison of Coagulation Conditions in Patients With Liver Cirrhosis Due to Primary Sclerosing Cholangitis and Nonbiliary Causes of Cirrhosis Before Orthotopic Liver Transplant

OBJECTIVES

Orthotopic liver transplant can be accompanied by an obscure bleeding pattern in patients with severe hepatic malfunction. In the present study, coagulation conditions of patients with cirrhosis of the liver due to primary sclerosing cholangitis and nonbiliary causes of cirrhosis were compared using rotational thromboelastometry assays obtained before orthotopic liver transplant.

MATERIALS AND METHODS

This case control study analyzed patients who were candidates for orthotopic liver transplant from 2010 to 2016. Eighty patients with cirrhosis of the liver (40 patients with primary sclerosing cholangitis and 40 with nonbiliary causes of cirrhosis) were randomly selected and enrolled into the study. Patients received rotational thromboelastometry assays under anesthesia just before the start of the operation, and results were compared between the 2 patient groups.

RESULTS

Of 80 patients, 52 were men and 28 were women. In the assays, we found that maximum amplitudes in 10 and in 20 minutes and maximum clot firmness parameters were higher in patients with primary sclerosing cholangitis. The alpha angle and clot formation time were different in the intrinsic and extrinsic assay panels. In the intrinsic assay, we found clotting time to be shorter (P < .05). The average of all parameters in all 3 assays (intrinsic, extrinsic, and fibrinogen contribution) was lower in patients with nonbiliary causes of cirrhosis than in those with primary sclerosing cholangitis.

CONCLUSIONS

In contrast with previous studies that found that patients with primary sclerosing cholangitis are hypercoagulable, our study observed that they have normal coagulable results. Furthermore, we found that, although mean coagulation indexes in patients with primary sclerosing cholangitis were within normal ranges, in patients with nonbiliary causes of cirrhosis, these indexes were generally lower.

Tailored classification of portal vein thrombosis for liver transplantation: Focus on strategies for portal vein inflow reconstruction

Portal vein thrombosis (PVT) is currently not considered a contraindication for liver transplantation (LT), but diffuse or complicated PVT remains a major surgical challenge. Here, we review the prevalence, natural course and current grading systems of PVT and propose a tailored classification of PVT in the setting of LT. PVT in liver transplant recipients is classified into three types, corresponding to three portal reconstruction strategies: Anatomical, physiological and non-physiological. Type I PVT can be removed via low dissection of the portal vein (PV) or thrombectomy; porto-portal anastomosis is then performed with or without an interposed vascular graft. Physiological reconstruction used for type II PVT includes vascular interposition between mesenteric veins and PV, collateral-PV and splenic vein-PV anastomosis. Non-physiological reconstruction used for type III PVT includes cavoportal hemitransposition, renoportal anastomosis, portal vein arterialization and multivisceral transplantation. All portal reconstruction techniques were reviewed. This tailored classification system stratifies PVT patients by surgical complexity, risk of postoperative complications and long-term survival. We advocate using the tailored classification for PVT grading before LT, which will urge transplant surgeons to make a better preoperative planning and pay more attention to all potential strategies for portal reconstruction. Further verification in a large-sample cohort study is needed.

The impact of ABO blood type on the prevalence of portal vein thrombosis in patients with advanced chronic liver disease

BACKGROUND AND AIMS

Non-O blood type (BT) is a risk factor for thromboses, which has been attributed to its effects on von Willebrand factor (VWF)/factor VIII (FVIII) levels. Although high VWF/FVIII may be risk factors for portal vein thrombosis (PVT) in patients with advanced chronic liver disease (ACLD), the impact of BT on PVT is unknown. We aimed to assess (I) whether non-O-BT is a risk factor for PVT and (II) whether non-O-BT impacts VWF/factor VIII in patients with ACLD.

METHODS

Retrospective analysis comprising two cohorts: (I) "US" including all adult liver transplantations in the US in the MELD era and (II) "Vienna" comprising patients with a hepatic venous pressure gradient (HVPG) ≥6 mmHg.

RESULTS

(I) The "US cohort" included 84 947 patients (non-O: 55.43%). The prevalence of PVT at the time of listing (4.37% vs 4.56%; P = .1762) and at liver transplantation (9.56% vs 9.33%; P = .2546) was similar in patients with O- and non-O-BT. (II) 411 patients were included in the "Vienna cohort" (non-O: 64%). Mean HVPG was 18(9) mmHg and 90% had an HVPG ≥10 mmHg. Patients with non-O-BT had slightly increased VWF levels (318(164)% vs 309(176)%; P = .048; increase of 23.8%-23.9% in adjusted analyses), but this difference was driven by patients with less advanced disease. However, non-O-BT explained only 1% of the variation in VWF and had no effect on FVIII.

CONCLUSIONS

Although non-O-BT impacts VWF in patients with early stage ACLD, its contribution to VWF variation is considerably smaller than in the general population. Moreover, non-O-BT had no impact on FVIII. These findings may explain the absence of an association between non-O-BT and PVT in patients with advanced cirrhosis.

Assessment and management of coagulopathy in critically-ill patients with liver failure

PURPOSE OF REVIEW

This review provides insight into our current understanding of the pathophysiology and treatment of coagulopathy associated with liver failure, and bleeding risk assessment.

RECENT FINDINGS

Patients with end-stage liver disease (ESLD) have a rebalanced coagulation profile and are at risk for both excessive clotting and bleeding. Hypercoagulability is associated with profound endothelial dysfunction and an increased concentration of liver-independent coagulation factors. Because of this rebalanced coagulation profile, standard laboratory tests have been demonstrated to be ineffective in either predicting and/or guiding the management of coagulopathy. Viscoelastic testing, however, is able to provide a dynamic assessment of clot formation in whole blood and has been demonstrated to be invaluable in both monitoring and management of coagulation problems associated with liver failure. More recently, there is increasing interest in thrombin generation tests to monitor coagulation in patients with ESLD.Multiple institutional protocols for prophylaxis and treatment of ESLD-related thromboses have been developed. High-quality studies evaluating these approaches are lacking.

SUMMARY

Patients with ESLD are at risk for excessive bleeding and clotting. Treatment of any significant coagulopathy should not be based solely on standard laboratory tests. Thrombosis prophylaxis has to be considered in susceptible populations.

Development of a Model to Predict Portal Vein Thrombosis in Liver Transplant Candidates: The Portal Vein Thrombosis Risk Index

Portal vein thrombosis (PVT) is associated with inferior pretransplantation and posttransplantation outcomes. We aimed to create a predictive model to risk stratify transplant candidates for PVT. Data on adult transplants in the United States during the Model for End-Stage Liver Disease (MELD) era through September 2016 were reviewed. We constructed and validated a scoring system composed of routine, readily available clinical information to predict the development of incident PVT at 12 months from transplantation listing. A total of 66,568 liver transplant candidates were dichotomized into 2 groups to construct (n = 34,751) and validate (n = 31,817) a scoring system. In general, the derivation and validation cohorts were clinically similar. Although nonalcoholic steatohepatitis was a significant predictor of incident PVT (hazard ratio, 1.29; 95% confidence interval, 1.08-1.54; P < 0.001), age, MELD score, and moderate-to-severe ascites were also associated with increased risk. African American race was associated with decreased risk. A scoring system (PVT risk index [RI]) of these 5 variables had an area under the curve of 0.71 and 0.70 in both derivation and validation cohorts, respectively. By applying the low cutoff score of 2.6, incident PVT could be accurately excluded (negative predictive value 94%). Using the high cutoff score of 4.6 (positive predictive value 85%), PVT could be diagnosed with high accuracy. The PVT-RI predicts which candidates awaiting lifesaving liver transplantation will and will not develop future PVT. Although this scoring system will require prospective validation, it provides a powerful new tool for the clinician when risk stratifying cirrhosis patients prior to liver transplantation for future PVT development.

Perioperative thrombotic complications associated with pediatric liver transplantation: a UNOS database evaluation

BACKGROUND

This retrospective UNOS database evaluation analyzes the prevalence of preoperative portal vein thromboses (PVT), and postoperative thromboses leading to graft failure in pediatric patients undergoing liver transplantation (LT).

METHODS

The evaluation was performed in three age groups: I (0-5), II (6-11), III (12-18) years old. Factors predictive of pre- and postoperative thromboses were analyzed.

RESULTS

Between 2000 and 2015, 8982 pediatric LT were performed in the US. Of those, 390 patients had preoperative PVT (4.3%), and 396 (4.4%) had postoperative thromboses. The prevalence of both types of thromboses was less in Group III than in the other two groups (3.20% vs 4.65%, p = 0.007 and 1.73% vs. 5.13%, p < 0.001, respectively). The prevalence of postoperative thromboses was significantly higher in Group I than in the other two groups (5.49% vs. 2.51%, p < 0.001). Preoperative PVT was independently associated with postoperative thromboses (OR = 1.7, p = 0.02). Children less than 5 years of age were more likely to develop postoperative thromboses leading to graft failure (OR = 2.9, p < 0.001).

CONCLUSION

Younger children undergoing LT are prone to pre-and postoperative thrombotic complications. Preoperative PVT at the time of transplantation was independently associated with postoperative thromboses. Perioperative antithrombotic therapy should be considered in pediatric patients undergoing LT.

Management of Non-tumoral Portal Vein Thrombosis in Patients with Cirrhosis

Non-tumoral portal vein thrombosis (PVT) remains a highly relevant topic in the field of hepatology and liver transplantation with much surrounding controversy. Although multiple studies have shown that PVT is associated with adverse outcomes with increased morbidity and mortality rates, others have not reported the same clinical impact of PVT, arguing rather that incident PVT reflects worsening portal hypertension and the natural history of the disease. Despite this uncertainly, PVT is a dilemma facing the clinician on a daily basis often requiring a multidisciplinary team-based approach between hepatologists, transplant surgeons, interventional radiologists and hematologists. In this review, the authors provide a summary of the evidence supporting best clinical practices in the management of non-tumoral PVT in patients with cirrhosis.

Treatment of primary sclerosing cholangitis in children

Primary sclerosing cholangitis (PSC) is a rare disease of stricturing and destruction of the biliary tree with a complex genetic and environmental etiology. Most patients have co-occurring inflammatory bowel disease. Children generally present with uncomplicated disease, but undergo a variable progression to end-stage liver disease. Within ten years of diagnosis, 50% of children will develop clinical complications including 30% requiring liver transplantation. Cholangiocarcinoma is a rare but serious complication affecting 1% of children. Ursodeoxycholic acid and oral vancomycin therapy used widely in children as medical therapy, and may be effective in a subset of patients. Gamma glutamyltransferase is a potential surrogate endpoint for disease activity, with improved survival in patients who achieve a normal value. Endoscopic retrograde cholangiopancreatography is a necessary adjunct to medical therapy to evaluate mass lesions or dominant strictures for malignancy, and also to relieve biliary obstruction. Liver transplantation remains the only option for patients who progress to end-stage liver disease. We review special considerations for patients before and after transplant, and in patients with inflammatory bowel disease. There is presently no published treatment algorithm or guideline for the management of children with PSC. We review the evidence for drug efficacy, dosing, duration of therapy, and treatment targets in PSC, and provide a framework for endoscopic and medical management of this complex problem.

Hypercoagulability in End-stage Liver Disease: Review of Epidemiology, Etiology, and Management

In this review, we analyze the epidemiology of thromboses related to end-stage liver disease (ESLD), discuss causes of hypercoagulability, describe susceptible populations, and critically evaluate proposed prophylaxis and treatment of thromboses. Classically, ESLD has been regarded as a model for coagulopathy, and patients were deemed to be at high risk for bleeding complications. Patients with ESLD are not auto-anticoagulated, and they do not have a lower risk of portal vein thrombosis, intracardiac thrombus formation, pulmonary embolism or hepatic artery thrombosis. Though the cause of hypercoagulability is multifactorial, endothelial dysfunction likely plays a central role for all patients with ESLD. Some subpopulations, such as patients with nonalcoholic steatohepatitis and autoimmune conditions, are at increased risk of thrombotic events as are patients of Hispanic ethnicity. The science behind prophylaxis of different types of clotting and treatment of thromboses is developing rapidly. A number of medications, including low molecular weight heparin, unfractionated heparin, aspirin, vitamin K antagonists, and direct oral anticoagulants can be used, but clear guidelines are lacking. Acute intraoperative clotting can be associated with high mortality. Routine use of transesophageal echocardiography can be helpful in early recognition and treatment of intraoperative thrombosis. Heparin should be reserved for cases of intracardiac thrombus/pulmonary embolism without hemodynamic instability. In unstable patients, low dose of recombinant tissue plasminogen activator can be used. In this new era of heightened awareness of thrombotic events in ESLD patients, prospective randomized trials are urgently needed to best guide clinical practice.

Fibrinolysis in Living Donor Liver Transplantation Recipients Evaluated Using Thromboelastometry: Impact on Mortality

BACKGROUND

Inadequate hemostasis during living donor liver transplantation (LDLT) is mainly due to coagulopathy but may also include fibrinolysis. The purpose of this study was to determine the incidence of fibrinolysis and assess its relevance to mortality in LDLT.

METHODS

The incidence and prognosis of fibrinolysis were retrospectively studied in 76 patients who underwent LDLT between April 2010 and February 2013. Fibrinolysis was evaluated and defined by maximum lysis (ML) >15% within a 60-minute run time using thromboelastometry (ROTEM).

RESULTS

Fibrinolysis was observed in 19 of the 76 (25%) patients before the anhepatic (pre-anhepatic) phase and was developed in 24 (32%) patients during and after the anhepatic (post-anhepatic) phase. In these 43 patients who had fibrinolysis, spontaneous recovery occurred in 29 patients (73%) within 3 hours after reperfusion of the liver graft. Recovery with tranexamic acid was noted in 2 patients with fibrinolysis in the post-anhepatic phase. Thrombosis in the portal vein and liver artery was noted in 14 patients, and the incidence was significantly greater in patients with post-anhepatic fibrinolysis than in those with pre-anhepatic fibrinolysis (P = .0017). Fibrinolysis that developed in the pre-anhepatic phase was associated with increased 30-day and 6-month mortalities (P = .0003 and .0026, respectively).

CONCLUSIONS

Fibrinolysis existed and developed in a large percentage of patients during LDLT. Thrombosis in the portal vein and hepatic artery was more common in patients with fibrinolysis in the post-anhepatic phase. Fibrinolysis that developed in the pre-anhepatic phase was associated with increased 30-day and 6-month mortalities.