Liver Transplantation: Intraoperative Transesophageal Echocardiography Findings and Relationship to Major Postoperative Adverse Cardiac Events

Impact of graft reperfusion on cardiac function assessed by transesophageal echocardiography during liver transplantation: an observational retrospective study

Cardiovascular instability is common during the reperfusion phase of orthotopic liver transplantation (OLT), and some patients experience a postreperfusion syndrome (PRS). However, there are no reports comparing the cardiac dysfunction between patients with PRS and those without. Thus, the aim of this study was to evaluate cardiac dysfunction in patients exhibiting PRS. This observational retrospective study included 34 patients who underwent OLT and were monitored with transesophageal echocardiography (TEE). The right ventricular/left ventricular (RV/LV) end diastolic area, tricuspid annular plane systolic excursion (TAPSE), left ventricular ejection fraction (LVEF) by Simpson method, pulsed Doppler of the mitral valve, and tissue Doppler motion of the mitral annulus were determined. Echocardiographic measurements were registered at the beginning of surgery and at 1 and 30 min after vascular unclamping. Patients with PRS (PRS group) were identified, and their echocardiographic parameters of ventricular function were compared with those in patients without PRS (non-PRS group). To check the evolution of diastolic-systolic dysfunction, general linear model-repeated measures were estimated. No patient presented systolic/diastolic dysfunction on the basal echocardiogram. One minute after vascular unclamping, the incidence of RV dilation was 4.5 times greater in patients with PRS (Cramer´s V > 0.6), and the incidence of RV systolic dysfunction was 62.5% in patients with PRS compared to 15.40% in patients without PRS (Cramer´s V = 0.45). The incidence of LV systolic dysfunction was 25% in patients with PRS compared to 0% in those without (Cramer´s V = 0.45), and left ventricular diastolic dysfunction was 4.8 times greater in patients with PRS (Cramer´s V = 0.45). No patient presented diastolic dysfunction type III. There were significant differences between groups in the evolutionary pattern at 1 and 30 min after unclamping for RV dilation (p = 0.008) and for TAPSE (p = 0.014). Liver graft reperfusion may alter cardiac function. Cardiac dysfunction was more frequent in patients with PRS. These patients exhibited temporary dysfunction of the RV associated with a varying degree of LV diastolic-systolic dysfunction. Trial registration: clinicaltrials.gov (NCT05175534). January 03, 2022; "retrospectively registered".

Intraoperative vascular air embolism and intracardiac thrombosis complicating liver transplantation: a case report

BACKGROUND

Intracardiac thrombus and vascular air embolism represent rare complications in the context of orthotopic liver transplantation. While isolated reports exist for intracardiac thrombus and vascular air embolism during orthotopic liver transplantation, this report presents the first documentation of their simultaneous occurrence in this surgical setting.

CASE PRESENTATION

This case report outlines the clinical course of a 60-year-old white female patient with end-stage liver disease complicated by portal hypertension, ascites, and hepatocellular carcinoma. The patient underwent orthotopic liver transplantation and encountered concurrent intraoperative complications involving intracardiac thrombus and vascular air embolism. Transesophageal echocardiography revealed the presence of air in the left ventricle and a thrombus in the right atrium and ventricle. Successful management ensued, incorporating hemodynamic support, anticoagulation, and thrombolytic therapy, culminating in the patient's discharge after a week.

CONCLUSIONS

This report highlights the potential for simultaneous intraoperative complications during orthotopic liver transplantation, manifesting at any phase of the surgery. It underscores the critical importance of vigilant monitoring throughout orthotopic liver transplantation to promptly identify and effectively address these rare yet potentially catastrophic complications.

Hemodynamic monitoring in liver transplantation 'the hemodynamic system'

PURPOSE OF REVIEW

The purpose of this article is to provide a comprehensive review of hemodynamic monitoring in liver transplantation.

RECENT FINDINGS

Radial arterial blood pressure monitoring underestimates the aortic root arterial blood pressure and causes excessive vasopressor and worse outcomes. Brachial and femoral artery monitoring is well tolerated and should be considered in critically ill patients expected to be on high dose pressors. The pulmonary artery catheter is the gold standard of hemodynamic monitoring and is still widely used in liver transplantation; however, it is a highly invasive monitor with potential for serious complications and most of its data can be obtained by other less invasive monitors. Rescue transesophageal echocardiography relies on few simple views and should be available as a standby to manage sudden hemodynamic instability. Risk of esophageal bleeding from transesophageal echocardiography in liver transplantation is the same as in other patient populations. The arterial pulse waveform analysis based cardiac output devices are minimally invasive and have the advantage of real-time beat to beat monitoring of cardiac output. No hemodynamic monitor can improve clinical outcomes unless integrated into a goal-directed hemodynamic therapy. The hemodynamic monitoring technique should be tailored to the patient's medical status, surgical technique, and the anesthesiologist's level of expertise.

SUMMARY

The current article provides a review of the current hemodynamic monitoring systems and their integration in goal-directed hemodynamic therapy.

Utility of transesophageal echocardiography during orthotopic liver transplantation: A narrative review

Orthotopic liver transplantation (OLT) is the standard of care for patients suffering from end stage liver disease (ESLD). This is a high-risk procedure with the potential for hemorrhage, large shifts in preload and afterload, and release of vasoactive mediators that can have profound effects on hemodynamic equilibrium. In addition, patients with ESLD can have preexisting coronary artery disease, cirrhotic cardiomyopathy, porto-pulomary hypertension and imbalanced coagulation. As cardiovascular involvement is invariable and patient are at an appreciable risk of intraoperative cardiac arrest, Trans esophageal echocardiography (TEE) is increasingly becoming a routinely utilized monitor during OLT in patients without contraindications to its use. A comprehensive TEE assessment performed by trained operators provides a wealth of information on baseline cardiac function, while a focused study specific for the ESLD patients can help in prompt diagnosis and treatment of critical events. Future studies utilizing TEE will eventually optimize examination safety, quality, permit patient risk stratification, provide intraoperative guidance, and allow for evaluation of graft vasculature.

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.

Intracardiac thrombosis and pulmonary thromboembolism during liver transplantation: A systematic review and meta-analysis

Intracardiac thrombosis and/or pulmonary thromboembolism (ICT/PE) is a rare but devastating complication during liver transplantation. Its pathophysiology remains poorly understood, and successful treatment remains a challenge. This systematic review summarizes the available published clinical data regarding ICT/PE during liver transplantation. Databases were searched for all publications reporting on ICT/PE during liver transplantation. Data collected included its incidence, patient characteristics, the timing of diagnosis, treatment strategies, and patient outcomes. This review included 59 full-text citations. The point prevalence of ICT/PE was 1.42%. Thrombi were most often diagnosed during the neohepatic phase, particularly at allograft reperfusion. Intravenous heparin was effective in preventing early-stage thrombus from progressing further and restoring hemodynamics in 76.32% of patients it was utilized for; however, the addition of tissue plasminogen activator or sole use of tissue plasminogen activator offered diminishing returns. Despite all resuscitation efforts, the in-hospital mortality rate of an intraoperative ICT/PE was 40.42%, with nearly half of these patients dying intraoperatively. The results of our systematic review are an initial step for providing clinicians with data that can help identify higher-risk patients. The clinical implications of our results warrant the development of identification and management strategies for the timely and effective treatment of these tragic occurrences during liver transplantation.

Using Transesophageal Echocardiography in Liver Transplantation with Veno-Venous Bypass Is a Tool with Many Applications: A Case Series from an Italian Transplant Center

BACKGROUND

Hemodynamic instability (HDI) is common during liver transplantation (LT); veno-venous bypass (VVB) is a tool used in selected cases to ensure hemodynamic stability and for surgical needs. Transesophageal echocardiography (TEE) allows the transplant team to identify the causes of HDI and to guide therapies. We present a case series of four patients showing the valuable role of TEE during LT in VVB.

METHODS

We report four explicative cases of TEE use in LT with VVB performed at IRCCS Azienda Ospedaliero-Universitaria di Bologna. Four transplants were performed between 2016 and 2022.

RESULTS

Many authors have highlighted the diagnostic value of TEE during LT in the case of HDI. However, its specific role during LT with VVB is poorly described. This paper illustrates multiple potential uses of TEE in LT with VVB: TEE as a guide for catheterization and optimal cannula positioning, TEE as a tool for intraoperative Patent Foramen Ovale management, TEE as help for anticoagulation therapy and finally, TEE as support when evaluating bypass efficiency and correcting hypovolemia.

CONCLUSION

TEE is a useful instrument during LT with VVB. However, further studies are needed to assess the suitable applications of TEE during LT in patients with HDI requiring VVB. TEE should be part of the anesthetist's cultural background.

Evaluation of right ventricular function during liver transplantation with transesophageal echocardiography

BACKGROUND

The pathophysiology of advanced liver cirrhosis may induce alterations in the circulatory system that may be challenging for the anesthesiologist to manage intraoperatively, and perioperative cardiovascular events are associated with worse outcomes in cirrhotic patients undergoing liver transplantation. It remains controversial whether right ventricular function is impaired during this procedure. Studies using transesophageal echocardiography for quantitative analysis of the right ventricle remain scarce in this setting, yielding conflicting results. The aim of this study was to perform a quantitative assessment of right ventricular function with two parameters derived from transesophageal echocardiography during liver transplantation.

METHODS

Nineteen adult patients of both genders undergoing liver transplantation were evaluated in this observational study. The exclusion criteria were age under 18 or above 65 years old, fulminant hepatic failure, hepatopulmonary syndrome, portopulmonary hypertension, cardiopulmonary disease, and contraindications to the transesophageal echocardiogram. Right ventricular function was assessed at five stages during liver transplantation: baseline, hepatectomy, anhepatic, postreperfusion, and closure by measuring tricuspid annular plane systolic excursion and right ventricular fractional area change obtained with transesophageal echocardiography.

RESULTS

Right ventricular function was found to be normal throughout the procedure. The tricuspid annular plane systolic excursion showed a trend toward a decrease in the anhepatic phase compared to baseline (2.0 ± 0.9 cm vs. 2.4 ± 0.7 cm; P = 0.24) but with full recovery after reperfusion. Right ventricular fractional area change remained nearly constant during all stages studied (minimum: 50% ± 10 at baseline and anhepatic phase; maximum: 56% ± 12 at postreperfusion; P = 0.24).

CONCLUSIONS

Right ventricular function was preserved during liver transplantation at the time points evaluated by two quantitative parameters derived from transesophageal echocardiogram.

Intraoperative intracardiac thrombus in liver transplantation: A 9-year retrospective review focusing on treatment and outcomes

This study characterizes incidence and outcomes surrounding intracardiac thrombosis (ICT) during liver transplantation over 9 years at a single center before and after the routine use of transesophageal echocardiography (TEE). Adult liver transplantation patients from 2011 to 2020 were divided into eras based on routine TEE use. ICTs were identified by querying anesthetic records for search terms. Descriptive statistics included counts and proportions for baseline recipient, donor, intraoperative, and postoperative characteristics. Outcome data were based on date of hospital discharge and date of death. The incidence of ICT increased in the TEE era (2016-2020) compared with the pre-TEE era (2011-2015; 3.7% [25/685] vs. 1.9% [9/491]; p < 0.001). Patients with ICT had significantly higher Model for End-Stage Liver Disease-sodium (MELD-Na) scores, pretransplant hospitalization, malignancy, drug-induced liver injury, hypertension, deep vein thrombosis, reperfusion syndrome, transfused platelets and cryoprecipitate, and use of hemostatic medications. A higher proportion of patients in the ICT group underwent simultaneous liver-kidney transplantation. The patients with ICT were similar, except patients in the pre-TEE era had higher MELD-Na scores and incidences of hepatitis C virus and lower incidences of encephalopathy. In the pre-TEE era, all ICTs presented as intraoperative cardiac arrest, and the 30-day mortality in the setting of ICT was 66.7% (6/9). During the TEE era, 80% of ICTs were diagnosed incidentally or attributed to hemodynamic instability (p = 0.002). The 30-day mortality rate was 36% (9/25) in the TEE era (p = 0.25). ICT incidence increased in the TEE era, yet the mortality rate was lower, suggesting that routine intraoperative TEE may lead to the early detection of ICT prior to hemodynamic collapse.

What is the optimal anesthetic monitoring regarding immediate and short-term outcomes after liver transplantation?-A systematic review of the literature and expert panel recommendations

BACKGROUND

Liver transplant centers vary in approach to intraoperative vascular accesses, monitoring of cardiac function and temperature management. Evidence is limited regarding impact of selected modalities on postoperative outcomes.

OBJECTIVES

To review the literature and provide expert panel recommendations on optimal intraoperative arterial blood pressure (BP), central venous pressure (CVP), and vascular accesses, monitoring of cardiac function and intraoperative temperature management regarding immediate and short-term outcomes after orthotopic liver transplant (OLT).

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Recommendations made for: (1) Vascular accesses, arterial BP and CVP monitoring, (2) cardiac function monitoring, and (3) Intraoperative temperature management (CRD42021239908).

RESULTS

Of 2619 articles screened 16 were included. Studies were small, retrospective, and observational. Vascular access studies demonstrated low rates of insertion complications. TEE studies demonstrated low rates of esophageal hemorrhage. One study found lower hospital-LOS and 30-day mortality in patients monitored with both PAC and TEE. Other monitoring studies were heterogenous in design and outcomes. Temperature studies showed increased blood transfusion and ventilation times in hypothermic groups.

CONCLUSIONS

Recommendations were made for; routine arterial and CVP monitoring as a minimum standard of practice, consideration of discrepancy between peripheral and central arterial BP in patients with hemodynamic instability and high vasopressor requirements, and routine use of high flow cannulae while monitoring for extravasation and hematoma formation. Availability and expertise in PAC and/or TEE monitoring is strongly recommended particularly in hemodynamic instability, portopulmonary HT and/or cardiac dysfunction. TEE use is recommended as an acceptable risk in patients with treated esophageal varices and is an effective diagnostic tool for emergency cardiovascular collapse. Maintenance of intraoperative normothermia is strongly recommended.

Systematic review with meta-analysis: incidence of variceal hemorrhage in patients with cirrhosis undergoing transesophageal echocardiography

BACKGROUND

The presence of esophageal varices is considered a relative contraindication to transesophageal echocardiography (TEE) by cardiology professional societies, so gastroenterologists are often consulted to perform upper endoscopy prior to TEE in patients with cirrhosis.

AIM

To perform a systematic review to quantify the risk of bleeding complications in patients with cirrhosis following TEE.

METHODS

Two reviewers searched Ovid MEDLINE, MEDLINE In-Process and EMBASE databases from January 1992 to May 2021 for studies reporting bleeding complications from TEE in patients with cirrhosis. We calculated the pooled incidence rate of bleeding events using the metaprop command with a random effect model.

RESULTS

We identified 21 studies comprising 4050 unique patients with cirrhosis; 9 studies (n = 3015) assessed the risk of intraoperative TEE during liver transplant (LT) and 12 studies (n = 1035) assessed bleeding risk in patients undergoing TEE for other indications. The pooled incidence of bleeding post-TEE was 0.37% (95% CI 0.04-0.94%) across all studies. Bleeding complications were low among patients undergoing TEE during LT as well as those undergoing TEE for other diagnostic reasons (0.97% vs. 0.004%) and among studies with mean MELD >18 compared to those with mean MELD <18 (0.43% vs. 0.08%). Few studies had a comparator arm, and data on patient-level factors impacting bleeding complications (including degree of liver dysfunction and coagulopathy) were limited across studies.

CONCLUSIONS

The risk of bleeding complications following TEE is low in patients with cirrhosis, suggesting TEE is safe and risk stratification with upper endoscopy may not be necessary.

Preliminary experience with continuous right ventricular pressure and transesophageal echocardiography monitoring in orthotopic liver transplantation

Background

Despite increasing attention in the cardiac anesthesiology literature, continuous measurement of right ventricular pressure using a pulmonary artery catheter has not been described in orthotopic liver transplantation, despite similarities in the anesthetic approach to the two populations. We describe our preliminary experience with this technique in orthotopic liver transplantation, and by combining various derived measures with trans-esophageal echocardiography, make some early observations regarding the response of these measures of right ventricular function during the procedure.

Methods

In this case series, ten patients (five men and five women) undergoing orthotopic liver transplantation in our institution had their surgeries performed while monitored with a pulmonary artery catheter with continuous right ventricular port transduction and trans-esophageal echocardiography. We recorded various right ventricular waveform (early-to-end diastolic pressure difference, right ventricular outflow tract gradient, right ventricular dP/dT and right ventricular end-diastolic pressure) and echocardiographic (right ventricular fractional area change, tricuspid annular plane systolic excursion, right ventricular lateral wall strain) and described their change relative to baseline at timepoints five minutes before and after portal vein reperfusion, immediately after hepatic artery reperfusion and on abdominal closure.

Results

Except for tricuspid annular plane systolic excursion at five minutes prior to reperfusion (mean −0.8 cm; 95% CI−1.4, –0.3; p = 0.007), no echocardiographic metric was statistically significantly different at any timepoint relative to baseline. In contrast, changes in right ventricular outflow tract gradient and right ventricular dP/dt were highly significant at multiple timepoints, generally peaking immediately before or after reperfusion before reducing, but not returning to baseline in the neohepatic phase. Nine of 10 participants in this series demonstrated a degree of dynamic right ventricular outflow tract obstruction, which met criteria for hemodynamic significance (> 25 mmHg) in two participants. These changes were not materially affected by cardiac index.

Conclusions

Dynamic right ventricular outflow tract obstruction of varying severity appears common in patients undergoing orthotopic liver transplantation. These results are hypothesis generating and will form the basis of future prospective research.

New onset nonischemic cardiomyopathy post liver transplantation

A new onset acute heart failure (HF) with a sudden drop in the left ventricular ejection fraction (LVEF) post orthotopic liver transplant (LT) is a rare but a potentially fatal complication. Because in most of the cases there is no evidence of coronary thrombosis, it can be classified as nonischemic cardiomyopathy. More specifically, clinical presentation of this syndrome shares many features with stress-induced or takotsubo cardiomyopathy. The known factors that predispose these patients to acute HF during or shortly after LT include cirrhotic cardiomyopathy, rapid hemodynamic changes during LT surgery, and the large concentrations of catecholamines, either administered or released endogenously during surgery. The hemodynamic changes during surgery, such as the drop in preload during the anhepatic phase (occasionally requiring massive transfusions and vasopressors) and subsequent increase in preload with acidic and hyperkalemic plasma in the reperfusion phase, lead to rapid electrolyte and hemodynamic shifts. In several cases, intraoperative onset of HF, with or without ventricular arrythmia, could be timed to the reperfusion phase (and occasionally in the anhepatic and pre-anhepatic phases). In other cases, the HF syndrome started hours to days post-surgery. Recovery of cardiac function occurred in the majority of patients during the same admission; however, these patients generally need significantly longer hospitalizations and aggressive supportive care (occasionally requiring mechanical ionotropic and ventilatory support). If recover, the patients have a similar 1-year mortality as those LT patients that did not have this complication. Because no reliable risk stratification currently exists, intraoperative transesophageal echocardiography might be the most dependable way of detecting and addressing this syndrome promptly. Given the mechanism of takotsubo cardiomyopathy, beta-blockade and a preferential use of non-catecholaminergic vasopressors may be a reasonable way to manage this syndrome.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

The Challenging Management of an Intracardiac Thrombus in a Liver Transplant Patient at the Reperfusion Phase: A Case Report and Brief Literature Review

The exact origin of intracardiac thrombi formation during orthotopic liver transplant remains unknown. The altered balance between hypercoagulability, hypocoagulation, and endothelial dysfunction associated with end-stage liver disease is thought to play a pivotal role. Venous stasis, vascular clamping, and reperfusion could also contribute to clot formation. The incidence of intracardiac thrombi formation stands at 4.2%, associated with a mortality rate of 45.5%, and to date, no consensus exists regarding the best way to treat this complication. Intraoperative transesophageal echocardiography is the only effective method for diagnosing intracardiac thrombi formation early, while point-of-care coagulation testing could guide the coagulation management potentially improving patient outcomes.

Safety and Benefit of Transesophageal Echocardiography in Liver Transplant Surgery: A Position Paper From the Society for the Advancement of Transplant Anesthesia (SATA)

More anesthesiologists are routinely using transesophageal echocardiography (TEE) during liver transplant surgery, but the effects on patient outcome are unknown. Transplant anesthesiologists are therefore uncertain if they should undergo additional training and adopt TEE. In response to these clinical questions, the Society for the Advancement of Transplant Anesthesia appointed experts in liver transplantation and who are certified in TEE to evaluate all available published evidence on the topic. The aim was to produce a summary with greater explanatory power than individual reports to guide transplant anesthesiologists in their decision to use TEE. An exhaustive search recovered 51 articles of uncontrolled clinical observations. Topics chosen for this study were effectiveness and safety because they were a major or minor topic in all articles. The pattern of clinical use was a common topic and was included to provide contextual information. Summarized observations showed effectiveness as the ability to make a new and unexpected diagnosis and to direct the choice of clinical management. These were reported in each stage of liver transplant surgery. There were observations that TEE facilitated rapid diagnosis of life-threatening conditions difficult to identify with other types of monitoring commonly used in the operating room. Real-time diagnosis by TEE images made anesthesiologists confident in their choice of interventions, especially those with a high risk of complications such as use of anticoagulants for intracardiac thrombosis. The summarized observations in this systematic review suggest that TEE is an effective form of monitoring with a safety profile similar to that in cardiac surgery patients.

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.

Influence of Intraoperative Transesophageal Echocardiography and Pulmonary Artery Catheter Monitoring on Outcomes in Liver Transplantation

Anesthetic management of orthotopic liver transplantation (OLT) can be challenging. Management involves responding to sudden hemodynamic shifts, addressing instability, and performing ongoing volume assessment. To best prepare for these perturbations, various monitors are used intraoperatively. We sought to explore the impact of transesophageal echocardiography (TEE) and pulmonary artery catheter (PAC) use on outcomes of patients undergoing OLT.

Perioperative management of antithrombotic treatment

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

The relationship between coronary artery disease and cardiovascular events early after liver transplantation

BACKGROUND & AIMS

Cardiovascular complications are major contributors to mortality at liver transplantation (LT). However, the impact of coronary artery disease (CAD) on these complications is not well-understood as the literature is limited by non-invasive assessment of CAD, which is suboptimal in patients with cirrhosis. Thus, the current study evaluated cardiovascular events at LT stratified according to the presence and severity of CAD quantified on coronary angiography.

METHODS

All patients who had LT from January 2010 to January 2017 were evaluated (N = 348), but analysis was restricted to patients who had coronary angiography prior to LT (N = 283). Protocol coronary angiography was performed in all patients' ages >50 years, history of CAD, abnormal cardiac stress test or risk factors for CAD. The primary outcome was a cardiovascular composite outcome including myocardial infraction (MI), cardiac arrest, stroke, cardiac death, heart failure or arrhythmia occurring within 4 weeks after LT.

RESULTS

CAD was present in 92(32.5%) patients and 32(11.3%) had obstructive CAD. During the study period, 72(25.4%) patients met the primary cardiovascular outcome, the most common being arrhythmia (N = 59 or 20.8%). Non-ST elevation MI occurred in 11(3.9%) of patients. A total of 10 deaths (3.5%) occurred, of which 6(2.1%) were attributable to cardiac death. There was no evidence of a relationship between the presence and severity of CAD and composite cardiovascular events. In multiple regression modelling, only diabetes [OR 2.62, 95%CI (1.49, 4.64), P < 0.001] was associated with the likelihood of having a cardiovascular event.

CONCLUSION

Cardiovascular disease mortality is the most important contributor of early mortality after LT but is not related to the severity of CAD.

Intraoperative Management to Prevent Cardiac Collapse in a Patient With a Recurrent, Large-volume Pericardial Effusion and Paroxysmal Atrial Fibrillation During Liver Transplantation: A Case Report

BACKGROUND

Pericardial effusion is a common feature of end-stage liver disease. In this case report we describe the intraoperative management of recurrent pericardial effusion, without re-pericardiocentesis, to prevent circulatory collapse during a critical surgical time-point; that is, during manipulation of the major vessels and graft reperfusion.

METHODS

A 47-year-old woman with hepatitis B was scheduled to undergo deceased donor liver transplantation (LT). A large pericardial effusion was preoperatively identified using transthoracic echocardiography (TTE). The patient also had paroxysmal atrial fibrillation. Two days before surgery, preemptive pericardiocentesis was performed and the 1150-mL effusion was drained. Intraoperatively, recurrence of the large pericardial effusion was identified using transesophageal echocardiography (TEE). During inferior vena cava manipulation, the surgeon consulted the anesthesiologist to evaluate the hemodynamic changes in the patient. After 3 attempts, the transplant team was able to determine the most appropriate anastomosis site, defined as that with the least impact on cardiac function. To prevent the development of severe postreperfusion syndrome, 10% MgSO₄ (2 g) was gradually infused 20 minutes before portal vein declamping, and immediately before graft reperfusion a 100-μg bolus of epinephrine was administered.

RESULTS

During graft reperfusion, there was no evidence of heart chamber collapse or flow disturbance, as seen on the TEE findings. Postoperatively, the patient recovered completely and was discharged from the hospital. Six months after surgery, there was no sign of pericardial effusion on follow-up TTE.

CONCLUSION

Our intraoperative strategy may prevent cardiac collapse in patients with pericardial effusion detected during LT. Intraoperative TEE plays an important role in guiding hemodynamic management.

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.

Transesophageal ultrasonography during orthotopic liver transplantation: Show me more

The first perioperative transesophageal echocardiography (TEE) guidelines published 21 years ago were mainly addressed to cardiac anesthesiologists. TEE has since expanded its role outside this setting and currently represents an invaluable tool to assess chamber sizes, ventricular hypertrophy, and systolic, diastolic, and valvular function in patients undergoing orthotopic liver transplantation (OLT). Right-sided microemboli, right ventricular dysfunction, and patent foramen ovale (PFO) are the most common intra-operative findings described during OLT. However, left ventricular outflow tract obstruction and left ventricular ballooning syndrome are more difficult to recognize and less frequent. Transesophageal ultrasonography (TEU) during OLT is also underused. Its applications are as follows: (1) assistance in the difficult placement of pulmonary arterial catheters; (2) help with catheterization of great vessels for external veno-venous bypass placement; (3) intra-operative evaluation of surgical liver anastomosis patency, if feasible, through the liver window; and (4) intra-operative investigation of "acute hypoxemia" due to pulmonary and cardiac issues using trans-esophageal lung ultrasound (TELU). The aims of this review are as follows: (1) to summarize the uses of TEE and TEU throughout all phases of OLT, and (2) to describe other new feasible applications.

Successful Removal of Intracardiac Thrombus With a Poole Tip Suction Device Through the Inferior Vena Cava of a Patient With Cardiovascular Collapse During Liver Transplant: A Case Report

Intracardiac thrombus occurs in 1.2%-6.3% of patients undergoing orthotopic liver transplant and is associated with a high mortality rate. The pathophysiology and risk factors for development of this complication are not well understood. No consensus treatment guidelines exist, and specific therapies are associated with serious risks. We present the timely and successful use of a Poole tip surgical suction device advanced into the right atrium through a cavotomy created in the inferior vena cava to remove a large right atrial thrombus during liver transplant. The thrombus was identified with transesophageal echocardiography and was causing cardiovascular collapse.

Noninvasive assessment of Cardiac Index using impedance cardiography during liver transplantation surgery: a comparison with pulmonary artery thermodilution

BACKGROUND

Liver transplantation (LT) is a high-risk surgery associated with significant hemodynamic changes requiring advanced hemodynamic monitoring. Pulmonary Artery Catheter (PAC) is still considered as a gold-standard for Cardiac Index (CI) measurement during LT despite association with an increased risk of complications. Noninvasive impedance cardiography (ICG) could be an interesting alternative tool for CI monitoring. The aim of this study was to compare the precision and trending ability of ICG versus PAC methods during LT.

METHODS

Patients undergoing LT were prospectively included. CI was measured with PAC and ICG at 4 time points (T1: before surgical incision, T2: during anhepatic phase, T3: after portal reperfusion, T4: during wound closure). Bias and percentage error (PE) between CI measured with PAC and ICG were analyzed with the Bland-Altman method for repeated measurements. Trending ability was studied with 4-quadrant and polar plots and correlation coefficient.

RESULTS

We included 43 patients with 156 measures. Mean bias was -0.95 L.min-1.m-2, SD±1.07, limits of agreement -3.73 to 1.83 L.min-1.m-2 and PE 58%. There was a significant increase in bias during LT (P<0.001). Assessment of trending ability displayed a concordance rate of 72% on the 4-quadrant plot and a mean angular bias of -8.4° (SD±28°) and radial limits of agreement ±55° on the polar plot.

CONCLUSIONS

CI measurements using ICG exhibited a low precision and a poor trending ability when compared to thermodilution method during LT. Consequently, ICG is not an adequate hemodynamic tool to monitor CI during LT.

A Comprehensive Review of Transesophageal Echocardiography During Orthotopic Liver Transplantation

Orthotopic liver transplantation (OLT) is characterized by significant hemodynamic disturbances and anesthetic challenges. Intraoperative transesophageal echocardiography (TEE) can be used to guide management during these procedures. This review examines the role of echocardiography during OLT, presents common TEE findings during each phase of OLT, and discusses the benefits demonstrated with TEE use and the safety of TEE in this patient population. Finally, the authors propose an algorithm for the safe use of TEE during OLT.

Comparative Effectiveness and Harms of Intraoperative Transesophageal Echocardiography in Noncardiac Surgery: A Systematic Review

Intraoperative use of transesophageal echocardiography (TEE) has become commonplace in high-risk noncardiac surgeries but the balance of benefits and harms remains unclear. This systematic review investigated the comparative effectiveness and harms of intraoperative TEE in noncardiac surgery. We searched Ovid MEDLINE, PubMed, EMBASE, and the Cochrane Library from 1946 to March 2017. Two reviewers independently screened the literature for eligibility. Studies were assessed for the risk of selection bias, confounding, measurement bias, and reporting bias. Three comparative and 13 noncomparative studies were included. Intraoperative TEE was employed in a total of 1912 of 3837 patients. Studies had important design limitations. Data were not amenable to quantitative synthesis due to clinical and methodological diversity. Reported incidence of TEE complications ranged from 0% to 1.7% in patients undergoing various procedures (5 studies, 540 patients). No serious adverse events were observed for mixed surgeries (2 studies, 197 patients). Changes in surgical or medical management attributable to the use of TEE were noted in 17% to 81% of patients (7 studies, 558 patients). The only randomized trial of intraoperative TEE was grossly underpowered to detect meaningful differences in 30-day postoperative outcomes. There is lack of high-quality evidence of effectiveness and harms of intraoperative TEE in the management of non-cardiac surgeries. Evidence, however, indicates timely evaluation of cardiac function and structure, and hemodynamics. Future studies should be comparative evaluating confounder-adjusted impact on both intraoperative and 30-day postoperative clinical outcomes.

Transesophageal echocardiography in orthotopic liver transplantation: a comprehensive intraoperative monitoring tool

Intraoperative transesophageal echocardiography is a minimally invasive monitoring tool that can provide real-time visual information on ventricular function and hemodynamic volume status in patients undergoing liver transplantation. The American Association for the Study of Liver Diseases states that transesophageal echocardiography should be used in all liver transplant candidates in order to assess chamber sizes, hypertrophy, systolic and diastolic function, valvular function, and left ventricle outflow tract obstruction. However, intraoperative transesophageal echocardiography can be used to "visualize" other organs too; thanks to its proximity and access to multiple acoustic windows: liver, lung, spleen, and kidney. Although only limited scientific evidence exists promoting this comprehensive use, we describe the feasibility of TEE in the setting of liver transplantation: it is a highly valuable tool, not only as a cardiovascular monitoring, but also as a tool to evaluate lungs and pleural spaces, to assess hepatic vein blood flow and inferior vena cava anastomosis and patency, i.e., in cases of modified surgical techniques. The aim of this case series is to add our own experience of TEE as a comprehensive intraoperative monitoring tool in the field of orthotopic liver transplantation (and major liver resection) to the literature.

Transoesophageal echocardiography during orthotopic liver transplantation

Despite the importance of haemodynamic management in patients undergoing liver transplantation, there is currently no consensus on the most appropriate type of monitoring to use. In this context, transoesophageal echocardiography can provide useful information to professionals, although their use constraints prevent further spread today.

Noteworthy Literature Published in 2016 for Abdominal Organ Transplantation Anesthesiologists

More than 3000 peer-reviewed publications on the topic of liver transplantation were published in 2016. The goal of this article is to provide a concise review of pertinent literature for anesthesiologists who participate in liver transplantation. The authors selected and presented 33 articles published in 2016 on the topics of MELD policy; cardiovascular, pulmonary, and renal issues; coagulation and transfusion; anesthetic agents; hemodynamic monitors; acute liver failure; and donor issues.

Emergent Management of Intracardiac Thrombosis during Liver Transplantation

Intraoperative thromboembolism is a well-documented complication associated with orthotopic liver transplantation (OLT) but its identification and intraoperative treatment are still an emerging topic in anesthesia. Intracardiac thrombus during OLT is associated with a high mortality rate. There are only a few reports describing the successful management of thromboembolism during OLT. We describe a case where routine intraoperative transesophageal echocardiography during a live donor liver transplantation enabled early detection of an intracardiac thrombus with subsequent successful heparin treatment. Our case suggests that if an intracardiac thrombus is identified early (before hemodynamic instability occurs), the use of IV heparin may be a safe therapeutic option.

Intraoperative Diagnosis of Intracardiac Thrombus During Orthotopic Liver Transplantation With Transesophageal Echocardiography: A Case Series and Literature Review

Anesthesia for orthotopic liver transplantation (OLT) is challenging for any anesthesiologist as the patients undergoing this procedure are among the most critically ill. Adding to the underlying complexity of OLT management is the rare complication of an intracardiac thrombus (ICT). Intracardiac thrombi can present following liver allograft reperfusion resulting in high morbidity and mortality. Currently there is no consensus treatment for ICT, and the gold standard for diagnosis is intraoperative transesophageal echocardiography (TEE); these 2 factors lead to a dangerous amalgam of the difficulty in diagnosing and treating the disease. We describe 2 separate cases in detail of ICT formation during OLT that were recognized and diagnosed with intraoperative TEE. These 2 cases highlight the important role of TEE in the management of ICT. A thorough literature review that follows analyzes our current understanding of ICT during OLT and the vital function of TEE by every anesthesiologists regardless of formal TEE training. Broader use of TEE during all OLTs can help narrow the anesthesiologist’s differential diagnosis during the acute phases of transplantation and should be considered in all liver transplant surgeries.