A hypercoagulable state follows orthotopic liver transplantation

Antithrombin supplementation for prevention of vascular thrombosis after pediatric liver transplantation

AIMS

After liver transplantation (LT), synthesis of coagulation factors by the graft recovers faster for pro thrombotic than anti thrombotic factors, resulting in a potential pro thrombotic imbalance. We studied the thrombotic and hemorrhagic complications in our pediatric LT series, providing supplementation of fresh frozen plasma (FFP) and/or antithrombin (AT) in the prophylactic antithrombotic regimen.

METHODS

This was a retrospective observational single center study. All isolated pediatric LTs performed between 1/11/2009 and 31/12/2019 (n = 181) were included. Postoperatively, in addition to low molecular weight heparin, 22 patients (12%) received FFP (10 ml/kg twice daily for 10 days), 27 patients (15%) were given FFP (reduced duration) and AT (50-100 IU/kg/day if AT activity remained <70%), and 132 (73%) received AT only. Complications, outcome, and coagulation profiles in postoperative days 0-10 were analyzed.

RESULTS

In all three treatment groups, AT activity normalized by day 4 while prothrombin remained <70% of normal until day 9. Hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and hemorrhagic complications occurred in 2.8%, 3.3%, and 3.9% of LTs. One- and 5-year patient and graft survival were 88% (±2.4% Standard Error) and 84% (±2.5%), and 86% (±2.6%) and 84% (±2.7%), respectively, without difference between groups. HAT were associated with low AT on days 0 and 1, and PVT with low AT on day 0.

CONCLUSIONS

Low antithrombin activity after LT was associated with postoperative thromboses. FFP and/or AT supplementation allowed early normalization of AT activity, while thrombotic or hemorrhagic complications were rare, suggesting efficient and safe management of post-LT coagulopathy.

Coagulopathy and hemostasis management in patients undergoing liver transplantation: Defining a dynamic spectrum across phases of care

Patients with acute and chronic liver disease present with a wide range of disease states and severity that may require liver transplantation (LT). Physiologic alterations occur that are dynamic throughout all phases of perioperative care, creating complex management scenarios that necessitate multidisciplinary clinical care. Specifically, alterations in hemostasis in liver disease can be pronounced and evolve with disease progression over time. Recent studies and society guidance address this emerging paradigm and offer recommendations to assist with hemostatic management in patients with liver disease. However, patients undergoing LT are unique and diverse, often with unstable disease that requires specialized approaches. Our aim is to provide a focused review of hemostatic management of the LT patient, distinguish unique aspects of the three main phases of care (before LT, perioperative, and after LT), and identify knowledge gaps and critical areas of future research.

Is there a procoagulant state long-term after lung transplantation? A prospective study

BACKGROUND

Venous thromboembolism (VTE) is a major complication after lung transplantation (LT). However, its pathophysiology remains unknown, and coagulation profiles have yet to be described.

OBJECTIVE

The aim of this study was to longitudinally assess coagulation status after LT.

METHODS

We performed a prospective study and described the coagulation profiles of 48 patients at 5 different time-points: before LT and at 24-72 h, 2 weeks, 4 months, and 1 year after LT.

RESULTS

At baseline, almost all analyzed coagulation factors were within the normal range, except for FVIII, which was above the normal range. Von Willebrand factor (vWF) and FVIII were increased after LT and remained high at 1 year after transplantation. The cumulative incidence of VTE was 22.9%. Patients who developed VTE had higher FVIII activity 2 weeks after LT.

CONCLUSIONS

This is the first study to describe coagulation profiles up to 1 year after LT. We show that most markers of a procoagulant state normalize at 2 weeks after LT, but that values of FVIII and vWF remain abnormal at 1 year. This problem has received little attention in the literature. Larger studies are necessary to confirm the results and to design appropriate prophylactic strategies.

Massive Pulmonary Artery Thromboembolism in a Liver Transplant Recipient: Case Study and Literature Review

The hypercoagulable state in liver transplant recipients that may manifest as abnormal thrombus formation in large vessel structures, such as cardiac chambers and the pulmonary arteries, poses a substantial threat for the patient and graft survival. Massive pulmonary embolism is a rare, albeit potentially lethal, complication that may occur at any stage of liver transplant surgery. In this study, we present the case of a major perioperative thromboembolic event in a liver transplant recipient that had taken place in the early post-transplant period during the second-look surgery that was then successfully treated by catheter-directed clot removal. We will attempt to identify potential factors that may have been associated with abnormal thrombus formation.

Liver function after transplantation in the assessment of the coagulation system and the concept of antithrombotic therapy

Introduction

Thrombotic complications after liver transplantation limit the long-term success of the procedure. Therefore, an early and accurate diagnosis with the appropriate treatment is crucial to sustain the proper functioning of the graft.

Aim

To evaluate the return of newly transplanted liver function within the first days of ICU stay after liver transplantation surgery (Ltx) observed in laboratory examination. It is important to understand the physiology of the newly transplanted liver, particularly in terms of its metabolic function and the assessment of easy-to-monitor coagulation parameters and enzyme markers.

Material and methods

We present our observations carried out in 27 patients, transplanted in the period 2015-2017, during their stay in the Department of Anaesthesiology and Intensive Therapy of the University Hospital in Wroclaw. We demonstrated changes in laboratory parameters within 72 h after liver transplantation and the concept of anticoagulant therapy at our institution.

Results

The presented results show the characteristics of aspartate transaminase, alanine transaminase, bilirubin, and standard tests evaluating the coagulation system within the first 4 days after surgery. The concept of anticoagulant therapy used in our intensive care unit is also presented. The aim of the work is an observation of physiology of the graft function in the aspect of coagulation disorders.

Conclusions

The early postoperative period is considered prognostic. The characteristics of basic biochemical tests are determined by the function of the transplanted organ. Implementation of anticoagulant therapy in this period is a therapeutic challenge that requires experience.

Antithrombin III in the prevention of thrombotic complications in high risk patients undergoing liver transplantation

Introduction. Recent studies have indicated an increased incidence of thrombotic vascular complications after liver transplantation. The reasons may be associated with surgical technique and “unbalanced” hemostasis in patients with diffuse liver diseases. The imbalance is determined by the deficiency of physiological procoagulants and anticoagulants due to a reduced protein-synthesis function of the liver in chronic hepatocyte injury. At the same time, 90% of all spontaneous antithrombin activity is associated with antithrombin III.

Aim. The aim of the study was to evaluate the efficacy of using antithrombin III concentrate in liver transplant patients.

Material and methods. A retrospective study included 46 patients undergoing liver transplantation who had nonocclusive thrombosis in the portal vein system prior to surgery and postoperative venous or arterial thrombosis.

Results. The treatment results were compared between the group with antithrombin III concentrate and the control group in patients with portal vein thrombosis before surgery and postoperative venous or arterial thrombosis; the antithrombin III activity dynamics in the early postoperative period was assessed; the incidence of infectious, and vascular complications and the mortality rates were analyzed.

Conclusion. The antithrombin III concentrate administration during liver transplantation and in the postoperative period contributes to a rapid normalization of antithrombin III activity in blood, the decrease in mortality and in the incidence of infectious and thrombotic complication rates.

Perioperative Thromboelastometry for Adult Living Donor Liver Transplant Recipients with a Tendency to Hypercoagulability: A Prospective Observational Cohort Study

Background

Hypercoagulability can lead to serious thromboembolic events. The aim of this study was to assess the perioperative coagulation status in liver transplant recipients with a tendency to hypercoagulability.

Methods

In a prospective observational study (South African Cochrane Registry 201405000814129), 151 potential liver transplant recipients were screened for thrombophilic factors from October 2014 to June 2017, and 57 potential recipients fulfilled the inclusion criterion of presenting two or more of the following thrombophilic factors: low protein C, low protein S, low anti-thrombin, increased homocystein, increased antiphospholipid IgG/IgM antibodies, increased lupus anticoagulant, and positive Factor V Leiden mutation. Seven patients were excluded from the study because they fulfilled the exclusion criteria of cancelling the liver transplantation, oral anticoagulation, or intraoperative treatment with rFVIIa. Accordingly, 50 patients were included in the final analysis. Thromboelastometry (ROTEM) (EXTEM, INTEM and FIBTEM) and conventional coagulation tests (CCT) were performed preoperatively, during the anhepatic phase, post reperfusion, and on postoperative days (POD) 1, 3 and 7. ROTEM was used to guide blood product transfusion. Heparin was infused (60-180 U/kg/day) postoperatively for 3 days and then was replaced by low-molecular-weight heparin (20 mg/12 h).

Results

FIBTEM MCF significantly increased postoperatively above reference range on POD 7 despite normal fibrinogen plasma concentrations (p < 0.05). Both EXTEM and INTEM demonstrated significant changes with the phases of transplantation (p < 0.05), but with no intra- or postoperative hypercoagulability observed. INTEM CT (reference range, 100-240 s) normalized on POD 3 and 7 (196.1 ± 69.0 and 182.7 ± 63.8 s, respectively), despite prolonged aPTT (59.7 ± 18.7 and 46.4 ± 15.7 s, respectively; reference range, 20-40 s). Hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT) were reported in 12.0% and 2.0%, respectively, mainly after critical care discharge and with high FIBTEM MCF values in 57% on POD 3 and 86% on POD 7. Receiver operating characteristics curve analyses of FIBTEM MCF were significant predictors for thromboembolic events with optimum cut-off, area under the curve and standard error on POD 3 (>23 mm, 0.779 and 0.097; p = 0.004) and POD 7 (>28 mm, 0.706 and 0.089; p = 0.020). Red blood cells (mean ± SD, 8.68 ± 5.81 units) were transfused in 76%, fresh frozen plasma (8.26 ± 4.14 units) in 62%, and cryoprecipitate (12.0 ± 3.68 units) in 28% of recipients. None of the recipients received intraoperative platelet transfusion or any postoperative transfusion. Main transplant indication was hepatitis C infection in 82%. 76% of recipients included in this highly selected patient population showed increased lupus anticoagulant, 2% increased antiphospholipid IgG/IgM antibodies, 20% increased homocysteine, 74% decreased anti-thrombin, 78% decreased protein C, 34% decreased protein S, and 24% a positive Factor V Leiden mutation. Overall 1-year survival was 62%.

Conclusion

A significant postoperative step-wise increase in FIBTEM MCF beyond the reference range was observed despite normal fibrinogen plasma concentrations, and FIBTEM MCF was a predictor for thromboembolic events in this study population, particularly after POD 3 and 7 on surgical wards when CCTs failed to detect this condition. However, the predictive value of FIBTEM MCF for postoperative HAT and PVT needs to be confirmed in a larger patient population. A ROTEM-guided anticoagulation regime needs to be developed and investigated in future studies.

Perioperative Thromboelastometry for Adult Living Donor Liver Transplant Recipients with a Tendency to Hypercoagulability: A Prospective Observational Cohort Study

BACKGROUND

Hypercoagulability can lead to serious thromboembolic events. The aim of this study was to assess the perioperative coagulation status in liver transplant recipients with a tendency to hypercoagulability.

METHODS

In a prospective observational study (South African Cochrane Registry 201405000814129), 151 potential liver transplant recipients were screened for thrombophilic factors from October 2014 to June 2017, and 57 potential recipients fulfilled the inclusion criterion of presenting two or more of the following thrombophilic factors: low protein C, low protein S, low anti-thrombin, increased homocystein, increased antiphospholipid IgG/IgM antibodies, increased lupus anticoagulant, and positive Factor V Leiden mutation. Seven patients were excluded from the study because they fulfilled the exclusion criteria of cancelling the liver transplantation, oral anticoagulation, or intraoperative treatment with rFVIIa. Accordingly, 50 patients were included in the final analysis. Thromboelastometry (ROTEM) (EXTEM, INTEM and FIBTEM) and conventional coagulation tests (CCT) were performed preoperatively, during the anhepatic phase, post reperfusion, and on postoperative days (POD) 1, 3 and 7. ROTEM was used to guide blood product transfusion. Heparin was infused (60-180 U/kg/day) postoperatively for 3 days and then was replaced by low-molecular-weight heparin (20 mg/12 h).

RESULTS

FIBTEM MCF significantly increased postoperatively above reference range on POD 7 despite normal fibrinogen plasma concentrations (p < 0.05). Both EXTEM and INTEM demonstrated significant changes with the phases of transplantation (p < 0.05), but with no intra- or postoperative hypercoagulability observed. INTEM CT (reference range, 100-240 s) normalized on POD 3 and 7 (196.1 ± 69.0 and 182.7 ± 63.8 s, respectively), despite prolonged aPTT (59.7 ± 18.7 and 46.4 ± 15.7 s, respectively; reference range, 20-40 s). Hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT) were reported in 12.0% and 2.0%, respectively, mainly after critical care discharge and with high FIBTEM MCF values in 57% on POD 3 and 86% on POD 7. Receiver operating characteristics curve analyses of FIBTEM MCF were significant predictors for thromboembolic events with optimum cut-off, area under the curve and standard error on POD 3 (>23 mm, 0.779 and 0.097; p = 0.004) and POD 7 (>28 mm, 0.706 and 0.089; p = 0.020). Red blood cells (mean ± SD, 8.68 ± 5.81 units) were transfused in 76%, fresh frozen plasma (8.26 ± 4.14 units) in 62%, and cryoprecipitate (12.0 ± 3.68 units) in 28% of recipients. None of the recipients received intraoperative platelet transfusion or any postoperative transfusion. Main transplant indication was hepatitis C infection in 82%. 76% of recipients included in this highly selected patient population showed increased lupus anticoagulant, 2% increased antiphospholipid IgG/IgM antibodies, 20% increased homocysteine, 74% decreased anti-thrombin, 78% decreased protein C, 34% decreased protein S, and 24% a positive Factor V Leiden mutation. Overall 1-year survival was 62%.

CONCLUSION

A significant postoperative step-wise increase in FIBTEM MCF beyond the reference range was observed despite normal fibrinogen plasma concentrations, and FIBTEM MCF was a predictor for thromboembolic events in this study population, particularly after POD 3 and 7 on surgical wards when CCTs failed to detect this condition. However, the predictive value of FIBTEM MCF for postoperative HAT and PVT needs to be confirmed in a larger patient population. A ROTEM-guided anticoagulation regime needs to be developed and investigated in future studies.

Effects of plasma transfusions on antithrombin levels after paediatric liver transplantation

BACKGROUND AND OBJECTIVES

Thrombotic complications affect 3-10% of patients after liver transplantation (LT), leading to potentially life-threatening complications. In the days following LT, antithrombin (AT) is decreased longer than pro-coagulant factors, thus favouring a pro-thrombotic profile. Plasma transfusions are given empirically in some centres to correct AT levels following LT. We assessed the effect of plasma transfusion on AT levels after paediatric LT.

MATERIALS AND METHODS

Prospective single-centre observational study in 20 consecutive paediatric LT recipients over a 24-month period. Plasma was administered twice daily (10 ml/kg/dose) according to an existing protocol. AT levels were measured once daily, immediately prior to and one hour after the morning plasma transfusion. Sample size was calculated based on a non-inferiority hypothesis.

RESULTS

The median age and weight were 11.6 years (IQR 2.8; 14.7) and 40 kg (IQR 12.75; 44.8), respectively. We collected 85-paired blood samples. The median AT level prior to plasma transfusion was 58%. The median difference in AT levels before and after plasma transfusion was 4.2% (P = 0.001). Changes in AT levels after plasma transfusion were not correlated with baseline AT levels (R = 0.19) or patient weight (R = 0.18).

CONCLUSION

Plasma transfusions only marginally increase AT levels in children after LT. Therefore, prophylactic plasma transfusions probably do not seem to confer an advantage in the routine management of paediatric LT patients. Randomized controlled trials are needed to identify the optimal anticoagulation strategy in this specific population.

Reducing the incidence of hepatic artery thrombosis in pediatric liver transplantation: Effect of microvascular techniques and a customized anticoagulation protocol

We aimed to assess the incidence of HAT over three eras following implementation of microvascular techniques and a customized anticoagulation protocol in a predominantly cadaveric split liver transplant program. We retrospectively reviewed pediatric liver transplants performed between April 1986 and 2016 and analyzed the incidence HAT over three eras. In E1, 1986-2008, each patient received a standard dose of 5 U/kg/h of heparin and coagulation profiles normalized passively. In E2, 2008-2012, microvascular techniques were introduced. In E3, 2012-2016, in addition, a customized anticoagulation protocol was introduced which included replacement of antithrombin 3, protein C and S, and early heparinization. A total of 317 liver transplants were completed during the study period, with a median age of 31.7 months. In E1, 22% of grafts were cadaveric in situ split grafts, while the second and third eras used split grafts in 59.0% and 64.9% of cases, respectively. HAT occurred in 9.5% in the first era, 11.5% (P=.661) in the second, and dropped to 1.8% in the third era (P=.043). A routine anticoagulation protocol has significantly reduced the incidence of HAT post-liver transplantation in children in a predominantly cadaveric in situ split liver transplant program.

Preoperative Thromboelastography as a Sensitive Tool Predicting Those at Risk of Developing Early Hepatic Artery Thrombosis After Adult Liver Transplantation

BACKGROUND

Whilst causes of hepatic artery thrombosis (HAT) after liver transplantation (LT) are multifactorial, early HAT (E-HAT) remains pertinent complication impacting on graft and patient survival. Currently there is no screening tool that would identify patients with increased risk of developing E-HAT.

METHODS

We analyzed the native procoagulant state of LT recipients, identified through pretransplant thromboelastographic (TEG) data among other known risk factors, to identify risk factors for E-HAT.

RESULTS

The outcomes of 828 adult patients undergoing LT between 2008 and 2013 were analyzed. Overall, 79 (9.5%) patients experienced HAT, E-HAT was diagnosed in 23, and in the remainder this was "late" HAT. The maximum amplitude (MA) on preoperative TEG was significantly higher in patients diagnosed with E-HAT compared with those who did not (71.2 mm vs 57.9 mm; P < 0.0001). Receiver operating characteristic analysis with the cutoff value for MA of 65 mm or greater returned area under the curve of 0.750 (P < 0.001) predicting E-HAT with a sensitivity of 70%. A total of 7% of patients with an MA of 65 mm or greater went on to develop E-HAT (hazard ratio, 5.28; 95% confidence interval, 2.10-12.29; P < 0.001), whereas only 1.2% patients with an MA less than 65 mm experienced E-HAT.

CONCLUSIONS

Preoperative TEG may reliably identify group of recipients at greater risk of developing E-HAT, and intense surveillance and anticoagulation prophylaxis may avoid this serious complication after LT.

Genetic, hematological, and immunological disorders transmissible with liver transplantation

It is well recognized that solid organ transplantation can transmit bacterial infection and chronic viral hepatitis as well as certain cancers. As indications for liver transplantation (LT) have expanded, it has been used to treat and even cure certain genetic cholestatic disorders, urea cycle defects, and coagulation abnormalities; many of these conditions are potentially transmissible with LT as well. It is important for clinicians and transplant patients to be aware of these potentially transmissible conditions as unexplained post-LT complications can sometimes be related to donor transmission of disease and thus should prompt a thorough exploration of the donor allograft history. Herein, we will review the reported genetic, metabolic, hematologic, and immunological disorders that are transmissible with LT and describe clinical scenarios in which these cases have occurred, such as in inadvertent or recognized transplantation of a diseased organ, domino transplantation, and with living related liver donation. Liver Transplantation 23 663-678 2017 AASLD.

Deep Vein Thrombosis and Pulmonary Embolism in Liver Transplant Patients: Risks and Prevention

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are surgical complications estimated to occur in 5% to 10% of patients. There are limited data regarding DVT/PE in the early postoperative period in liver transplant patients. The aim of this study is to determine risk factors that influence the incidence of DVT/PE and the effectiveness of prophylaxis.

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.

Pediatric transplantation: preventing thrombosis

Due to progressive advances in surgical techniques, immunosuppressive therapies, and supportive care, outcomes from both solid organ transplantation and hematopoietic stem cell transplantation continue to improve. Thrombosis remains a challenging management issue in this context, with implications for both graft survival and long-term quality of life. Unfortunately, there remains a general paucity of pediatric-specific data regarding thrombosis incidence, risk stratification, and the safety or efficacy of preventative strategies with which to guide treatment algorithms. This review summarizes the available evidence and rationale underlying the spectrum of current practices aimed at preventing thrombosis in the transplant recipient, with a particular focus on risk factors, pathophysiology, and described antithrombotic regimens.

Trigger mechanisms of secondary sclerosing cholangitis in critically ill patients

INTRODUCTION

In recent years the development of secondary sclerosing cholangitis in critically ill patients (SSC-CIP) has increasingly been perceived as a separate disease entity. About possible trigger mechanisms of SSC-CIP has been speculated, systematic investigations on this issue are still lacking. The purpose of this study was to evaluate the prevalence and influence of promoting factors.

METHODS

Temporality, consistency and biological plausibility are essential prerequisites for causality. In this study, we investigated the temporality and consistency of possible triggers of SSC-CIP in a large case series. Biological plausibility of the individual triggers is discussed in a scientific context. SSC-CIP cases were recruited retrospectively from 2633 patients who underwent or were scheduled for liver transplantation at the University Hospital Charité, Berlin. All patients who developed secondary sclerosing cholangitis in association with intensive care treatment were included. Possible trigger factors during the course of the initial intensive care treatment were recorded.

RESULTS

Sixteen patients (68% males, mean age 45.87 ± 14.64 years) with a confirmed diagnosis of SSC-CIP were identified. Of the 19 risk factors investigated, particularly severe hypotension with a prolonged decrease in mean arterial blood pressure (MAP) to <65 mmHg and systemic inflammatory response syndrome (SIRS) were established as possible triggers of SSC-CIP. The occurrence of severe hypotension appears to be the first and most significant step in the pathogenesis. It seems that severe hypotension has a critical effect on the blood supply of bile ducts when it occurs together with additional microcirculatory disturbances.

CONCLUSIONS

In critically ill patients with newly acquired cholestasis the differential diagnosis of SSC-CIP should be considered when they have had an episode of haemodynamic instability with a prolonged decrease in MAP, initial need for large amounts of blood transfusions or colloids, and early development of a SIRS.

Do postliver transplant patients need thromboprophylactic anticoagulation?

Postoperative thromboprophylactic anticoagulation against Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) is standard of care with current evidence-based guidelines. However, majority of liver transplant (LT) patients have thrombocytopenia and/or prolonged INR before surgery. Studies or guidelines regarding role of prophylactic anticoagulation after LT are lacking. There is a need to balance the risk of thrombosis with significant hemorrhage, implying those needing transfusion or return to OR due to bleeding. We conclude that after LT, anticoagulation is not required routinely for DVT/PE prophylaxis. Rather, it is indicated in specific circumstances, chiefly for prophylaxis of hepatic artery thrombosis or portal vein thrombosis in cases with use of grafts, pediatric cases, small size vessels, Budd Chiari syndrome, amongst others.

Prediction of postoperative mortality in liver transplantation in the era of MELD-based liver allocation: a multivariate analysis

BACKGROUND AND AIMS

Liver transplantation is the only curative treatment for end-stage liver disease. While waiting list mortality can be predicted by the MELD-score, reliable scoring systems for the postoperative period do not exist. This study's objective was to identify risk factors that contribute to postoperative mortality.

METHODS

Between December 2006 and March 2011, 429 patients underwent liver transplantation in our department. Risk factors for postoperative mortality in 266 consecutive liver transplantations were identified using univariate and multivariate analyses. Patients who were <18 years, HU-listings, and split-, living related, combined or re-transplantations were excluded from the analysis. The correlation between number of risk factors and mortality was analyzed.

RESULTS

A labMELD ≥20, female sex, coronary heart disease, donor risk index >1.5 and donor Na+>145 mmol/L were identified to be independent predictive factors for postoperative mortality. With increasing number of these risk-factors, postoperative 90-day and 1-year mortality increased (0-1: 0 and 0%; 2: 2.9 and 17.4%; 3: 5.6 and 16.8%; 4: 22.2 and 33.3%; 5-6: 60.9 and 66.2%).

CONCLUSIONS

In this analysis, a simple score was derived that adequately identified patients at risk after liver transplantation. Opening a discussion on the inclusion of these parameters in the process of organ allocation may be a worthwhile venture.

Low plasma levels of antithrombin III in the early post-operative period following pediatric liver transplantation: should they be replaced? A single-center pilot study

eHAT after LT remains a life-threatening complication. In the majority of anticoagulation protocols, heparin is used to prevent thromboses. Our study aimed to monitor AT-III levels in the early post-LT period to assess the need for the administration of AT-III concentrate to ensure the effectiveness of heparin. We monitored coagulation daily by measuring INR, APTT, fibrinogen, platelets, and AT-III. Anticoagulation therapy consisted of LMWH, AT-III, and dipyridamole. AT-III concentrate was administered when AT-III activity was ≤60%. DUS was performed daily for the first five post-operative days or whenever vascular thrombosis was suspected. Between October 2007 and October 2011, 39 LT were performed in our center. The median age was 26 months (6-196) with a median weight of 9 kg (5.5-49). AT-III activity was ≤60% in 27 patients. Lower levels were particularly observed in partial grafts and recipients weighing less than 10 kg. Patent arterial flow was present in all 39 LT during the first five post-operative days. AT-III levels were low in 70% of pediatric patients following LT, thereby risking heparin ineffectiveness. These results may implicate low AT-III levels in the etiology of eHAT post-LT. However, this is a small single-center pilot study and further larger prospective trials are required to confirm these results.

Perioperative management of liver transplantation with concurrent coronary artery disease: Report of two cases

Coronary artery disease (CAD), even if asymptomatic, has been known to complicate the perioperative management of patients undergoing liver transplantation. Perioperative outcome for such patients is worse than those without CAD despite improvement in risk stratification and management of CAD. We hereby report the successful perioperative management of two patients with CAD undergoing living-related liver transplantation. Maintaining systemic vascular resistance, goal-directed volume administration and surgical technique avoiding total clamping of IVC was the mainstay of stable intraoperative course. Moreover, a lower model for end stage liver disease (MELD) score at the time of liver transplant may also have been contributory to successful outcome in our patients.

Clinical utility of viscoelastic tests of coagulation in patients with liver disease

The prothrombin time (PT) and international normalised ratio (INR) are used in scoring systems (Child-Pugh, MELD, UKELD) in chronic liver disease and as a prognostic tool and for dynamic monitoring of hepatic function in acute liver disease. These tests are known to be poor predictors of bleeding risk in liver disease; however, they continue to influence clinical management decisions. Recent work on coagulation in liver disease, in particular thrombin generation studies, has led to a paradigm shift in our understanding and it is now recognised that haemostasis is relatively well preserved. Whole blood global viscoelastic tests (TEG(®) /ROTEM(®) ) produce a composite dynamic picture of the entire coagulation process and have the potential to provide more clinically relevant information in patients with liver disease. We performed a systematic review of all relevant studies that have used viscoelastic tests (VET) of coagulation in patients with liver disease. Although many studies are observational and small in size, it is clear that VET provide additional information that is in keeping with the new concepts of how coagulation is altered in these patients. This review provides the basis for large scale, prospective outcome studies to establish the clinical value of these tests.

Recipient and donor thrombophilia and the risk of portal venous thrombosis and hepatic artery thrombosis in liver recipients

Background

Vascular complications, such as HAT, are an important cause of graft loss and recipient mortality. We aimed to characterize post-transplant thrombotic events in a cohort of liver transplant recipients, and identify independent risk factors for these complications.

Methods

We conducted a thrombophilic study of 293 orthotopic liver transplants performed in the Digestive Surgery Department of the 12 de Octubre Hospital (Madrid, Spain) between January 2001 and December 2006.

Results

The most frequent post-transplant thrombotic events were HAT (9%) and PVT (1.7%). The one variable associated with post-transplant thrombotic event was a high fibrinogen level in the global cohort of liver transplantation. But toxicity as event post-OLT has been associated with post-transplant thrombotic event in the retrospective group and high fibrinogen level and low protein C levels were associated post-transplant thrombotic event in the prospective group. Liver disease relapse (HR 6.609, p < 0.001), high levels of FVIII (HR 1.008, p = 0.019)) and low levels of antithrombin (HR 0.946, p < 0.001) were associated with poor overall survival (OS).

In conclusion, high fibrinogen and decreased protein C levels were associated with allograft thrombosis. Further studies are required in order to assess the clinical relevance of these parameters in prospective studies and to study the effect of anticoagulation prophylaxis in this group of risk.

Hepatic artery reconstruction and successful management of its complications in living donor liver transplantation using a right lobe

BACKGROUND

The aim of the present study was to improve the techniques of hepatic artery (HA) reconstruction and to properly manage arterial complications after living donor liver transplantation (LDLT).

METHODS

Prospectively collected data collected from 371 patients who underwent adult LDLT using a right lobe from January 2000 to August 2009 were retrospectively reviewed.

RESULTS

Of 17 patients (4.6%, 17/371) with double HA stumps in the graft, 12 patients (70.6%) received dual HA reconstruction. HA complications were composed of thrombosis (n = 6), pseudoaneurysm (n = 2), and stenosis (n = 4), showing 3.2% (12/371) of incidence. In patients with HA thrombosis, whereas operative thrombectomies with re-anastomosis rescued all the grafts in early attack (n = 3, ≤1 wk), angiographic thrombolysis successfully reestablished the flow in patients with late attack (n = 3, >1 wk). In all patients with HA complications, except for one, all of our treatment modalities - operation and angiographic intervention - resulted in successful rescue of grafts and no patient received re-transplantation because of HA complications.

CONCLUSION

Prompt diagnosis of HA complications by serial post-operative Doppler ultrasound and corresponding treatment strategies, including operative and radiological intervention, can rescue both grafts and patients without necessitating re-transplantation.

Viscoelastic coagulation testing: technology, applications, and limitations

Use of viscoelastic point-of-care (POC) coagulation instrumentation is relatively new to veterinary medicine. In human medicine, this technology has recently undergone resurgence owing to its capacity to detect hypercoagulability. The lack of sensitive tests for detecting hypercoagulable states, along with our current understanding of in vivo coagulation, highlights the deficiencies of standard coagulation tests, such as prothrombin and partial thromboplastin times, which are performed on platelet-poor plasma. Viscoelastic coagulation analyzers can provide an assessment of global coagulation, from the beginning of clot formation to fibrinolysis, utilizing whole blood. In people, use of this technology has been reported to improve management of hemostasis during surgery and decrease usage of blood products and is being used as a rapid screen for hypercoagulability. In veterinary medicine, clinical use of viscoelastic technology has been reported in dogs, cats, foals, and adult horses. This article will provide an overview of the technology, reagents and assays, applications in human and veterinary medicine, and limitations of the 3 viscoelastic POC analyzers in clinical use.

Multivessel coronary artery disease predicts mortality, length of stay, and pressor requirements after liver transplantation

The optimal preoperative cardiac evaluation strategy for patients with end-stage liver disease (ESLD) undergoing liver transplantation remains unknown. Patients are frequently referred for cardiac catheterization, but the effects of coronary artery disease (CAD) on posttransplant mortality are also unknown. We sought to determine the contribution of CAD and multivessel CAD in particular to posttransplant mortality. We performed a retrospective study of ESLD patients undergoing cardiac catheterization before liver transplant surgery between August 1, 2004 and August 1, 2007 to determine the effects of CAD on outcomes after transplantation. Among 83 patients who underwent left heart catheterization, 47 underwent liver transplantation during the follow-up period. Twenty-one of all ESLD patients who underwent liver transplantation (45%) had CAD. Fifteen of the transplant patients with CAD (71%) had multivessel disease. Among transplant patients, the presence of multivessel CAD (versus no CAD) was predictive of mortality (27% versus 4%, P = 0.046), increased length of stay (22 versus 15 days, P = 0.050), and postoperative pressor requirements (27% versus 4%, P = 0.029). Interestingly, neither the presence of any CAD nor the severity of stenosis in any single coronary artery predicted mortality. Furthermore, none of the traditional clinical predictors (age, gender, diabetes, creatinine, ejection fraction, and Model for End-Stage Liver Disease score) were predictive of mortality among transplant recipients. In conclusion, multivessel CAD is associated with higher mortality after liver transplantation when it is documented angiographically before transplantation, even in the absence of severe coronary artery stenosis. This study provides preliminary evidence showing that there may be significant prognostic value in coronary angiography as a part of the pretransplant workup.

Pulmonary thromboembolism in liver transplantation: a retrospective review of the first 25 years

The evidence on the state of 'haemostasis' at the time of liver transplantation (LT) is conflicting, with recent publications that suggest a hypercoagulable state, in contrast to traditionally held views. These findings raise the issue of thrombo-embolic complications after LT, an area of interest which has received little attention in recent published literature. We therefore conducted a retrospective review of our experience of 3000 liver transplants over 25 years. Our prospective transplant database was reviewed to find all patients who were suspected to have had a pulmonary embolism (PE) during or following LT. Paediatric transplants were excluded. A part of this database was cross referenced against hospital records to corroborate its accuracy. Clinical records of all these patients were reviewed and relevant aspects collated and analyzed. Following exclusion of the paediatric recipients, 2 149 adults were reviewed to find 36 patients in whom a PE was suspected (median age 49), 21 of whom were within 90 days of transplant (median duration 22 days). PE was ruled out in 10, unconfirmed in two, confirmed in eight patients; and in one, air embolism was found. All PEs occurred in hospital, but aetiology of liver failure was varied. Of note, two patients died of an on-table PE and one patient of chronic rejection/disease recurrence (Primary Sclerosing Cholangitis). The remaining five are still alive (median survival of 65 months). Although thromboprophylaxis is now routine in our unit, its use in these patients could not be confirmed from records available. Fifteen PE were suspected and confirmed after 90 days from transplant (six within, and nine out with the first year). Acute PE in the setting of LT has an incidence rate in our series of 0.37% that would appear to be lower than previously reported and lower than one would expect after a 'major complex' category operation. This potentially suggests that the overall haemostatic function in these patients is still weighted towards hypocoagulation with the resultant risk of excessive bleeding. Aetiology of liver disease did not seem to confer a higher risk in our series. The prognosis after post-operative PE appears good although sudden death due to an on-table embolism is a rare but significant risk.

Evaluation of a post-operative thrombin inhibitor replacement protocol to reduce haemorrhagic and thrombotic complications after paediatric liver transplantation

INTRODUCTION

Bleeding and thrombotic complications contribute to morbidity and mortality following paediatric orthotopic liver transplantation (OLT). However, the pathophysiology of haemostasis during paediatric OLT is not well understood. This report consists of two complimentary studies examining the frequency of haemostatic complications before and after the introduction of a post-operative thrombin inhibitor replacement therapy protocol at a single institution.

MATERIALS AND METHODS

A retrospective study of 40 patients who underwent 43 liver transplants between July 1992 and July 2002, identified bleeding to be the most frequent complication associated with OLT (30%), however thrombotic complications were also common (12.5%). In 2003, following a detailed analysis of haemostatic profiles of children undergoing OLT, a thrombin inhibitor replacement protocol was introduced. A prospective clinical outcome audit was undertaken from April 2003 to September 2008 to determine the effect of the new protocol on haemostasis.

RESULTS

Commencement of the thrombin inhibitor replacement protocol significantly reduced the incidence of thrombosis (from 5 to 1, p<0.05), graft loss (from 4 to none, p<0.05), mortality due to thrombosis or bleeding (from 3 to none, p<0.05) and was associated with a 50% reduction in frequency of major bleeding.

CONCLUSION

In conclusion, the introduction of a post-operative thrombin inhibitor replacement therapy protocol following paediatric OLT significantly improved haemostasis-related morbidity and mortality outcomes in children.

Thrombotic events after pediatric liver transplantation

TE may contribute to morbidity and mortality after LT. The objectives were to determine the incidence of early TE post-pediatric LT and compare differences between children with and without TE. A retrospective review of 88 transplanted children (January 2002-October 2007) was performed to determine the incidence of Doppler-confirmed DVT and ATE in the first month post-LT. Fourteen (16%) patients developed TE: DVT in seven (8%) and ATE in seven (8%) patients. Six of 88 (6.8%) developed symptomatic CVL-related DVT. Median (range) time post-LT to DVT and ATE were 7 (4-18) and 8 (1-31) days, respectively. There was no significant difference in age/body weight at LT between patients with or without DVT and ATE. There was no significant difference between patients with or without HAT in age and weight at LT, cold ischemic time, duration of surgery, hematocrit levels, whole-organ graft type, intraoperative FFP, high-risk CMV status, or early acute cellular rejection. In conclusion, the incidence of early TE post-pediatric LT was 16%, including DVT in 8%. Prospective studies are necessary to evaluate the role of prophylactic anticoagulation and potential modifiable risk factors post-pediatric LT.

Normal to increased thrombin generation in patients undergoing liver transplantation despite prolonged conventional coagulation tests

BACKGROUND & AIMS

Patients with liver disease often show substantial changes in their hemostatic system, which may aggravate further during liver transplantation. Recently, thrombin generation in patients with stable disease was shown to be indistinguishable from controls provided thrombomodulin, the natural activator of the anticoagulant protein C system, was added to the plasma. These results indicated that the hemostatic balance is preserved in patients with liver disease, despite conventional coagulation tests suggest otherwise.

METHODS

Here we examined thrombin generation profiles in serial plasma samples taken from ten consecutive patients undergoing liver transplantation.

RESULTS

At all time points, the endogenous thrombin potential (ETP) was slightly lower compared to healthy volunteers, despite substantially prolonged PT and APTT values. However, when thrombin generation was tested in the presence of thrombomodulin, the ETP was equal to or even higher than that in healthy subjects. In fact, thrombin generation was hardly affected by thrombomodulin, while thrombin generation in healthy subjects decreased profoundly upon the addition of thrombomodulin. In patients undergoing liver transplantation, efficient thrombin generation in the presence of thrombomodulin may be explained by decreased levels of protein C, S, and antithrombin, and by elevated levels of FVIII.

CONCLUSIONS

Thrombin generation in patients undergoing liver transplantation is equal or even superior to thrombin generation in healthy volunteers when tested in the presence of exogenous thrombomodulin. These results support the recently advocated restrictive use of plasma during liver transplantation and warrants further study of the prophylactic use of anticoagulants to reduce thromboembolic complications after transplantation.

Administration of dalteparin based on the activated clotting time for prophylaxis of hepatic vessel thrombosis in living donor liver transplantation

Beginning in 2004, dalteparin doses based on activated clotting time (ACT) were administered for hepatic vessel thrombosis prophylaxis in living donor liver transplantation (LDLT). We verified the feasibility of this new therapy by comparing it with the previous one. From 1993 through 2008, 42 metabolic liver patients who underwent LDLT were divided into two groups. Group A (1993-2003, n = 32) was administered a fixed dalteparin dose and a large amount of fresh frozen plasma (FFP); Group B (2004-2008, n = 10) was administered an appropriate dosage of dalteparin to maintain the ACT levels from 140 to 150 seconds and a small amount of FFP. Group B was administered a lesser amount of FFP and more dalteparin. This resulted in longer activated partial thromboplastin time, lower fibrinogen degradation products D-dimer, and lower aspartate aminotransferase levels compared to group A; all differences were significant. Group B showed neither thrombotic nor hemorrhagic complications. Anticoagulation therapy comprising adjustment of the dalteparin dose based on ACT reduces thrombotic complications without increasing hemorrhagic complications. ACT measurement is a simple, reliable method for bedside monitoring of dalteparin anticoagulant effects for LDLT.

Comparison of viscoelastic coagulation analysis and standard coagulation profiles in critically ill neonatal foals to outcome

OBJECTIVE

To determine if changes in viscoelastic variables are associated with abnormalities observed in the standard coagulation profile and patient outcome in foals with suspected septicemia.

DESIGN

Prospective clinical trial during 2003 and 2004 foal season.

SETTING

Neonatal intensive care unit at a veterinary teaching hospital.

ANIMALS

Thirty critically ill foals <72-hour-old admitted sequentially meeting criteria for systemic inflammatory response associated with infection.

INTERVENTIONS

Hemostatic evaluation, using standard coagulation testing and viscoelastic analysis, was performed at admission, 24 hours following admission, and 48 hours following admission in critically ill foals. Standard coagulation tests included platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, fibrin(ogen) degradation products, and antithrombin. Data collected from viscoelastic analysis included time to initial clot formation (ACT), clot rate, and platelet function. Signalment, blood culture results, clinicopathologic data, and outcome were collected from medical records. Equality of populations test was used to determine associations between coagulation tests and blood culture status/outcome, as well as between viscoelastic parameters and coagulopathy, blood culture status, and outcome. Logistic regression was used to quantify associations. A significance level of P<0.05 was used.

MEASUREMENTS AND MAIN RESULTS

Foals with decreasing clot rate (CR) over the sample period were more likely to be euthanized or die (P=0.02). Foals with prolonged ACT (P=0.03), and decreased CR at admission (P=0.047), were more commonly coagulopathic. Identification of coagulopathy on admission (P=0.02), or persistence of hemostatic dysfunction 48 hours later (P=0.04), was associated with death.

CONCLUSIONS

Viscoelastic coagulation evaluation could be used in a neonatal intensive care unit setting to further characterize coagulopathy, and identify foals at higher risk for poor outcome.

Combined heart and liver transplantation: a single-center experience

BACKGROUND

Simultaneous combined orthotopic heart and liver transplantation (CHLTx) remains a lifesaving procedure for the patients suffering from coincident end-stage heart and liver disease and several metabolic disorders. We analyze the long-term outcome of the patients undergoing CHLTx.

METHODS

Between January 1992 and May 2007, 15 CHLTx were attempted at the Mayo Clinic including two combined heart, liver, and kidney transplantations and one combined heart, lung, and liver transplantations. Pretransplant cardiac diagnoses were familial amyloidosis (11), hemochromatosis (1), restrictive cardiomyopathy and cardiac cirrhosis (1), previously operated congenital heart disease and cardiac cirrhosis (1), and primary pulmonary hypertension with primary biliary cirrhosis (1).

RESULTS

Heart and liver transplantation were performed as a single combined procedure in 13 (93%) hemodynamically stable patients, and there was no perioperative mortality. Survival rates for the CHLTx recipients at 1 year, 5 years, and 10 years were 100%, 75%, and 60%, respectively, and did not differ from survival after isolated heart transplantation (93%, 83%, and 65%, respectively, P=0.39). Freedom from cardiac allograft rejection (ISHLT > or =grade 2) for CHLTx was 83% at 1 month, did not change with time, and was lower than after isolated heart transplantation (P=0.02). At the mean follow-up of 61.6+/-53.6 months, normal left ventricular ejection fraction and good liver allograft function were demonstrated. Three patients developed end-stage renal failure secondary to calcineurin nephrotoxicity.

CONCLUSION

Simultaneous heart and liver transplantation is feasible and achieved excellent results for selected patients.

Antithrombin effect on coagulation and fibrinolytic profiles after living donor liver transplantation: a pilot study

Early after liver transplantation, patients are in a hypercoagulable state because of an imbalance between coagulation and fibrinolysis because of the slow recovery of depleted anticoagulant proteins. Antithrombin (AT) is used in anticoagulant protocols to prevent thrombosis. The subjects of the present study were 17 men and eight women that underwent living donor liver transplantation. The initial 15 cases were administered AT concentrate (1500 U/day) on postoperative days (POD) 1 through 3 (AT group) and the following 10 consecutive cases were not administered AT (control). AT, thrombin-AT complex, plasmin-alpha2 plasmin inhibitor complex, thrombomodulin, fibrin degradation product D-dimer (FDP-DD) level, prothrombin time international normalized ratio, activated partial thromboplastin time, and platelet counts were measured. In the AT group, AT activity was maintained at levels >80% for 5 days after transplantation. In the control group, AT activity did not return to normal during the first 2 weeks after the operation. FDP-DD levels were significantly higher in the control group than in the AT group (P < 0.05). Six patients in the control group and three patients in the AT group required transfusions with platelet concentrate (P < 0.05). AT supplementation might reduce FDP-DD levels and prevent decreased platelet counts in the early stages after liver transplantation.

Predictive value of dobutamine stress echocardiography for coronary artery disease detection in liver transplant candidates

Patients with obstructive coronary artery disease (CAD) undergoing orthotopic liver transplantation (OLT) are at increased risk of poor outcomes. The accuracy of dobutamine stress echocardiography (DSE) to detect obstructive CAD is not well established in this population. We retrospectively identified patients with end-stage liver disease who underwent both DSE and coronary angiography as part of risk stratification prior to OLT. One hundred and five patients had both DSE and angiography, of whom 14 had known CAD and 27 failed to reach target heart rate during DSE. Among the remaining 64 patients (45 men; average age 61 +/- 8 years) DSE had a low sensitivity (13%), high specificity (85%), low positive predictive value (PPV) (22%) and intermediate negative predictive value (NPV) (75%) for obstructive CAD. DSE as a screening test for obstructive CAD in OLT candidates has a poor sensitivity. The frequent chronotropic incompetence and low sensitivity in patients who achieve target heart rate, even in those with multiple cardiovascular disease risk factors, suggest that alternative or additional methods of risk stratification are necessary.

Coagulation monitoring: current techniques and clinical use of viscoelastic point-of-care coagulation devices

Perioperative monitoring of blood coagulation is critical to better understand causes of hemorrhage, to guide hemostatic therapies, and to predict the risk of bleeding during the consecutive anesthetic or surgical procedures. Point-of-care (POC) coagulation monitoring devices assessing the viscoelastic properties of whole blood, i.e., thrombelastography, rotation thrombelastometry, and Sonoclot analysis, may overcome several limitations of routine coagulation tests in the perioperative setting. The advantage of these techniques is that they have the potential to measure the clotting process, starting with fibrin formation and continue through to clot retraction and fibrinolysis at the bedside, with minimal delays. Furthermore, the coagulation status of patients is assessed in whole blood, allowing the plasmatic coagulation system to interact with platelets and red cells, and thereby providing useful additional information on platelet function. Viscoelastic POC coagulation devices are increasingly being used in clinical practice, especially in the management of patients undergoing cardiac and liver surgery. Furthermore, they provide useful information in a large variety of clinical scenarios, e.g., massive hemorrhage, assessment of hypo- and hypercoagulable states, guiding pro- and anticoagulant therapies, and in diagnosing of a surgical bleeding. A surgical etiology of bleeding has to be considered when viscoelastic test results are normal. In summary, viscoelastic POC coagulation devices may help identify the cause of bleeding and guide pro- and anticoagulant therapies. To ensure optimal accuracy and performance, standardized procedures for blood sampling and handling, strict quality controls and trained personnel are required.

Intraoperative pulmonary embolism and intracardiac thrombosis complicating liver transplantation: a systematic review

BACKGROUND

Pulmonary embolism (PE) and intracardiac thrombosis (ICT) are rare but potentially lethal complications during orthotopic liver transplantation (OLT).

METHODS

We aimed to review clinical and pathological correlates of PE and ICT in patients undergoing OLT. A systematic review of the literature was conducted using MEDLINE and ISI Web of Science.

RESULTS

Seventy-four cases of intraoperative PE and/or ICT were identified; PE alone in 32 patients (43%) and a combination of PE and ICT in 42 patients (57%). Most frequent clinical symptoms included systemic hypotension and concomitant rising pulmonary artery pressure, often leading to complete circulatory collapse. PE and ICT occurred in every stage of the operation and were reported equally in patients with or without the use of venovenous bypass or antifibrinolytics. A large variety of putative risk factors have been suggested in the literature, including the use of pulmonary artery catheters or certain blood products. Nineteen patients underwent urgent thrombectomy or thrombolysis. Overall mortality was 68% (50/74) and 41 patients (82%) died intraoperatively.

CONCLUSION

Mortality was significantly higher in patients with an isolated PE, compared to patients with a combination of PE and ICT (91% and 50%, respectively; P < 0.001). Intraoperative PE and ICT during OLT appear to have multiple etiologies and may occur unexpectedly at any time during the procedure.