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.

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.

2021 Clinical Update in Liver Transplantation

In 2021, the United States performed 9,236 liver transplantations, an increase of 3.7% from 2020. As the specialty of transplant anesthesiologist continues to grow, so does the body of evidence-based research to improve patient care. New technology in organ preservation offers the possibility of preserving marginal organs for transplant or improving the graft for transplantation. The sequalae of end-stage liver disease have wide-ranging consequences that affect neurologic outcomes of patients both during and after transplantation that anesthesiologists should monitor. Obesity presents several challenges for anesthesiologists. As an increasing number of patients with nonalcoholic steatohepatitis are listed for transplant, managing their multiple comorbidities can be challenging. Finally, the rebalanced hemostasis of end-stage liver disease can cause both bleeding and thrombus. Often, bleeding risks predominate as a concern, but anesthesiologists should be aware of risks of intracardiac thrombus and review therapeutic options for prevention and treatment.

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.

Thrombolysis of a massive intracardiac thrombus during resuscitation: documentation by transoesophageal echocardiography

Acute pulmonary embolism is a frequent potentially reversible cause of sudden cardiac arrest. The early diagnosis is challenging but essential for further treatment. New therapeutic options in resuscitation, such as extracorporeal resuscitation, are leading to frequent transports of patients to emergency rooms with ongoing resuscitation. A transoesophageal echo performed during resuscitation can give hints for reversible causes for the cardiac arrest. We present a case of a 40-year-old female patient who was transferred to our department with ongoing resuscitation and received a transoesophageal echo immediately on arrival. The examination showed a massive intracardiac thrombus. The subsequent thrombolysis and following resuscitation were observed and documented via transoesophageal echo.

Acute heart failure after liver transplantation: A narrative review

Acute heart failure (AHF) is an under recognized yet potentially lethal complication after liver transplantation (LT) surgery. The increase in incidence of liver transplantation amongst high-risk patients and the leniency in the criteria for transplantation, predisposes these patients to postoperative AHF and the antecedent morbidity and mortality. The inability of conventional preoperative cardiovascular testing to accurately identify patients at risk for post-LT AHF poses a considerable challenge to clinicians caring for these patients. Even if high-risk patients are identified, there is considerable ambiguity in the candidacy for transplantation as well as optimization strategies that could potentially prevent the development of AHF in the postoperative period. The intraoperative and postoperative management of patients who develop AHF is also challenging and requires a well-coordinated multidisciplinary approach. The use of mechanical circulatory support in patients with refractory heart failure has the potential to improve outcomes but its use in this complex patient population can be associated with significant complications and requires a stringent risk-benefit analysis on a case-by-case basis.

Role of Transesophageal Echocardiography in the Diagnosis of Multi-chamber Intracardiac Thrombosis During Liver Transplantation: A Case Series

Intra-cardiac thrombosis is one of the most devastating complications during liver transplantation. In the majority of cases, ICT, followed by massive pulmonary embolism, is commonly occurring shortly after liver graft reperfusion, but it has been reported to occur at any stage of the surgery. We present a series of 3 cases of intra-cardiac thrombosis during orthotopic liver transplantation surgery, including a case of four-chamber intra-cardiac clot formation during the pre-anhepatic stage. This article represents a single-centre 14 year-long experience. Intra-operative TEE is the gold standard to diagnose intra-cardiac thrombosis, monitoring its size, location and dynamics, as well as myocardial performance and the effects of resuscitation efforts.

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.

Cardiac Thrombus Formation During Cardiopulmonary Resuscitation for Cardiac Arrest: Is It Time for Ultrasound-Enhanced Algorithms?

Current guidelines consider thrombosis as a potential (and reversible) cause of cardiorespiratory arrest (CA). However, cardiac thrombus formation (TF) is likely to be the consequence of the forward blood flow ceasing during cardiac standstill. We present the case of a young man who was hospitalized for infective endocarditis, complicated by multiorgan disease and sudden CA on the 5^th day. Prompt cardiopulmonary resuscitation (CPR) warranted a return of spontaneous circulation in 16 min but, unexpectedly, a TF was recognized in the right atrium at echocardiography. The blood clot resolved with rapid administration of endovenous heparin and continued chest compressions. Even though cardiac ultrasound is not ready for a routine use during CPR, the present study confirms a key role in the management of CA patients.

Utilization of extracorporeal membrane oxygenation for a severe cardiocirculatory dysfunction recipient in liver transplantation: A case report

RATIONALE

Severe cardiac dysfunction or severe pulmonary hypertension is a contraindication of liver transplantation (LT). Extracorporeal membrane oxygenation (ECMO) is an advanced therapy for severe lung and/or cardiocirculatory dysfunction or failure. The application of ECMO to patients during the LT perioperative period may help recipients with severe cardiac disease to maintain the heart function and alleviate the reperfusion syndrome.

PATIENT CONCERNS

A female liver recipient complained about weakness for 6 months.

DIAGNOSES

The patient was diagnosed as hepatitis B virus (HBV)-related hepatic cirrhosis (MELD 24, Child-Pugh C) with severe mitral regurgitation, severe tricuspid regurgitation, left atrium and left ventricle enlargement, cardiac insufficiency, pulmonary arterial hypertension, and hypoxemia.

INTERVENTIONS

The patient underwent LT from a cardiac deceased donor. The surgery was completed by venoarterial ECMO. The femoral vessels cannulation was done after the dissection of the patient's liver and before the venous blocking. Venous cannula reached to the position below renal vein, while arterial cannula reached to common iliac artery. We regulated the ECMO index according to the patient's condition. The dosage of heparin was adjusted on the basis of the activated clotting time. Respiratory support, milrinone, furosemide, and mannitol were used to improve the circulation. The bleeding volume of surgery was 1200 mL. The cardiocirculatory function and other vital signs remained good in the perioperative period. In the first 24 hours after surgery, central venous pressure decreased from 17 to 7 cmH2O. Thirty hours after surgery, the ECMO was removed. Eighteen hours later, the recipient did not need respiratory support.

OUTCOMES

No complications of transplantation or ECMO were found.

LESSONS

It is feasible to utilize ECMO as a cardiocirculatory function support in the LT. ECMO does not increase the risk of hemorrhage. ECMO can play an important role in ensuring the security of the liver recipients in the surgery and in the postoperative period.

Expanded Criteria Donor-Related Hyperkalemia and Postreperfusion Cardiac Arrest During Liver Transplantation: A Case Report and Literature Review

Background

Liver transplantation (LT) using extended criteria donor (ECD) grafts is frequently associated with a high flush fluid potassium concentration (FFK) and acute hyperkalemia after reperfusion, which puts patients at greater risk of postreperfusion cardiac arrest (PRCA).

Case Report

Herein, we present a case with an extremely high FFK that was successfully pretreated to avoid the risk of PRCA. A 3-year-old boy with biliary atresia underwent LT from a 623-g donation after brain death liver graft with localized frostbite on the right lobe surface. The FFK was 18.8 mmol/L after flushing with 1000 mL of 5% albumin. To prevent PRCA due to acute hyperkalemia, further portal vein (PV) flush, retrograde reperfusion via the inferior vena cava, and antegrade reperfusion via the PV were adopted to remove the excessive potassium ions. Ultimately, the liver graft was reperfused when the perfused blood potassium concentration was 7.5 mmol/L without subsequent development of PRCA during the immediate reperfusion period. Nevertheless, the patient still experienced vasoplegic syndrome during the late reperfusion period.

Conclusions

Our case illustrates that the FFK measurement is helpful for identifying ECD-related hyperkalemia and for providing advance warning of PRCA. Future investigations are warranted to confirm the relationship between high FFK and PRCA and to observe the effectiveness of other interventions to prevent PRCA due to ECD-related hyperkalemia.

Use, Training, and Opinions About Effectiveness of Transesophageal Echocardiography in Adult Liver Transplantation Among Anesthesiologists in the United States

Study Objective. Describe transesophageal echocardiography (TEE) use, preparatory training and opinions about clinical importance, and future training pathways in a sample of liver transplant anesthesiologists. Design. Online survey questionnaire. Setting. Liver Transplant Centers in the United States. Participants. Director of Liver Transplant Anesthesia or designated alternate respondent. Results. A total of 79 Directors or alternates from 111 (71%) centers were identified. There were 56 responses (71%) representing 433 transplant anesthesiologists who cared for 63.3% of liver transplant cases performed in 2015. Basic TEE certification was reported more frequently (64%) than advanced (53.6%). At least one team member used TEE in over 90% of responding centers. Most respondents (83.9%) agreed TEE provided unique and valuable clinical information but were equally divided about future training pathways (on the job learning vs basic TEE certification). Conclusion. TEE use in liver transplantation is growing with a substantial increase in basic TEE certified users. Transplant anesthesiologists support basic certification but an equal number believe there should be more applied training at the site of care.