Risk Factors for Intracardiac Thrombus During Liver Transplantation

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.

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.

Tranexamic Acid for Acute Hemorrhage: A Narrative Review of Landmark Studies and a Critical Reappraisal of Its Use Over the Last Decade

The publication of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) study and its intense dissemination prompted a renaissance for the use of the antifibrinolytic agent tranexamic acid (TXA) in acute trauma hemorrhage. Subsequent studies led to its widespread use as a therapeutic as well as prophylactic agent across different clinical scenarios involving bleeding, such as trauma, postpartum, and orthopedic surgery. However, results from the existing studies are confounded by methodological and statistical ambiguities and are open to varied interpretations. Substantial knowledge gaps remain on dosing, pharmacokinetics, mechanism of action, and clinical applications for TXA. The risk for potential thromboembolic complications with the use of TXA must be balanced against its clinical benefits. The present article aims to provide a critical reappraisal of TXA use over the last decade and a "thought exercise" in the potential downsides of TXA. A more selective and individualized use of TXA, guided by extended and functional coagulation assays, is advocated in the context of the evolving concept of precision medicine.

Fibrinolytic Shutdown Is Associated With Intraoperative Thrombosis and Hemorrhage During Visceral Transplant

Background and Objective. End-stage liver disease is characterized by a precarious imbalance of hemostasis. Detrimental consequences of hypofibrinolysis, also known as fibrinolytic shutdown, have been recently demonstrated, and its significance in visceral (ie, an allograft that contains the intestine) transplant remains unknown. Design and Setting. To fill this gap, following institutional review board approval, this retrospective study included 49 adult recipients of visceral allografts (14 “visceral allograft without the liver” and 35 “multivisceral” with the liver) transplanted between 2010 and 2018 in a single university hospital, and for whom pre-incisional thromboelastography was available. Based on percent clot lysis 30 minutes after maximal amplitude, patients were stratified into 3 fibrinolysis phenotypes: fibrinolytic shutdown, physiologic fibrinolysis, and hyperfibrinolysis. Results. Fibrinolytic shutdown occurred in 57% of patients, with higher incidence in recipients of multivisceral transplant (69%) compared with visceral allograft without liver (29%) allografts ( P = .04). Fibrinolytic shutdown was associated with an increase in both intraoperative thrombosis and hemorrhage. Intraoperative thrombosis (18%) occurred only with multivisceral transplant, and accounted for 36% of in-hospital mortality. A clinically meaningful reduction in incidence of intraoperative thrombosis was noted in recipients who received intravenous heparin thromboprophylaxis. Logistic regression identified pretransplant platelet count as a risk factor for fibrinolytic shutdown (odds ratio = 0.992, 95% confidence interval = [0.984-0.998]; χ2= 7.8, P = .005). Conclusions. This study highlights fibrinolytic shutdown as a dominant and clinically important feature of the hemostatic imbalance in recipients undergoing visceral transplantation.