Risk Factors for Intracardiac Thrombus During Liver Transplantation

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.

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.

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.

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.

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.

Research Priorities in Liver Transplant Anesthesiology: Results of a Survey of Liver Transplant Anesthesiologists

Optimal perioperative care contributes to improved patient outcomes, as demonstrated in the field of liver transplant (LT). The evolution in perioperative care over the past two decades has been driven by research in areas such as preoperative testing, coagulation management, and intraoperative monitoring. However, much of this research is driven by local institutional pressures and practices with a dearth of studies emanating from research consortia or other groups of experts within the field. To better characterize the top research questions in the field, we queried a group of 128 LT anesthesiologists representing 87 international liver transplant centers with a response from 71 practitioners (59.2%). Three experts then codified the responses into the top 20 questions, which were sent to the survey recipients as a second survey to rank order. Seventy-five respondents (61.5%) provided responses which were merged into a weighted ranked priority list and analyzed by respondent location and center size. The highest ranked question was, "What intraoperative anesthetic management/interventions affect graft outcome?" Most of the top research questions focused on preoperative risk factor management or optimization and intraoperative management techniques. In general, this priorities list may serve as a guide for transplant anesthesiology researchers to focus future research endeavors on shared interests that improve patient care. This article is protected by copyright. All rights reserved.

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.

Major Thromboembolic Complications in Liver Transplantation: The Role of Rotational Thromboelastometry and Cryoprecipitate Transfusion

BACKGROUND

Although hemorrhage is a major concern during liver transplantation (LT), the risk for thromboembolism is well recognized. Implementation of rotational thromboelastometry (ROTEM) has been associated with the increased use of cryoprecipitate; however, the role of ROTEM-guided transfusion strategy and cryoprecipitate administration in the development of major thromboembolic complications (MTCs) has never been documented.

METHODS

We conducted a study on patients undergoing LT before and after the implementation of ROTEM. We defined MTC as intracardiac thrombus, pulmonary embolism, hepatic artery thrombosis, and ischemic stroke in 30 d after LT. We used a propensity score to match patients during the 2 study periods.

RESULTS

Among 2330 patients, 119 (4.9%) developed MTC. The implementation of ROTEM was significantly associated with an increase in cryoprecipitate use (1.1 ± 1.1 versus 2.9 ± 2.3 units, P < 0.001) and MTC (4.2% versus 9.5%, P < 0.001). Further analysis demonstrated that the use of cryoprecipitate was an independent risk factor for MTC (odds ratio 1.1, 95% confidence interval 1.04-1.24, P = 0.003). Patients with MTC had significantly lower 1-y survival.

CONCLUSIONS

Our study suggests that the implementation of ROTEM and the use of cryoprecipitate play significant roles in the development of MTC in LT. The benefits and risks of cryoprecipitate transfusion should be carefully evaluated before administration.

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.

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.