Thrombotic and hemorrhagic complications during visceral transplantation: risk factors, and association with intraoperative disseminated intravascular coagulation-like thromboelastographic qualities: a single-center retrospective study

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.

Thromboelastography in the Perioperative Period: A Literature Review

Assessing coagulation status is essential for prompt intervention to reduce morbidity and mortality related to bleeding and thrombotic complications during the perioperative period. Traditional coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and activated clotting time (ACT) provide only static evaluation. These tests are not designed for assessment of dynamically changing coagulation conditions during the perioperative time. However, viscoelastic coagulation testing such as thromboelastography (TEG) produces a rapid numerical and graphical representation that helps to detect and direct targeted hemostatic therapy. Searching the literature through PubMed, Medline, Ovid, CINAHL, and ClinicalTrials.gov we retrieved 210 studies, which represent the use of TEG in the perioperative period. The included studies were categorized under various settings such as trauma, obstetrics, orthopedics, intensive care unit (ICU), cardiovascular, transplant, and miscellaneous scenarios. TEG showed promising results in trauma surgeries in predicting mortality, hypercoagulability, and bleeding even when it was compared to conventional methods. TEG was also useful in monitoring anticoagulant therapy in orthopedic and obstetric surgeries; however, its role in predicting thrombotic events, hypercoagulability, or complications was questionable. In ICU patients, it showed promising results, especially in the prediction or improvement of sepsis, coagulopathy, thrombotic events, ICU duration, hospital stay, and ventilator duration. TEG parameters effectively predicted hypercoagulation in transplant surgeries. Regarding cardiovascular surgeries, they were effective in the prediction of the need for blood products, coagulopathy, thrombotic events, and monitoring anticoagulation therapy. More randomized clinical trials comparing TEG parameters with standardized tools are needed to produce robust results to standardize its use in different perioperative settings.

Multivisceral Transplant in a Patient With Portopulmonary Hypertension: A Case Report

Portopulmonary hypertension, a type of pulmonary arterial hypertension in the setting of cirrhotic or noncirrhotic portal hypertension, is associated with elevated morbidity and mortality during and after transplantation. Uncontrolled portopulmonary hypertension may prevent or delay listing for transplant candidates, and the prognosis without treatment and ultimately transplant is extremely poor. We present a 29-year-old White woman, who had a post-liver transplant at infancy due to biliary atresia. Later on, she developed extensive portal vein thrombosis and portopulmonary hypertension and underwent a multivisceral transplant (liver, stomach, pancreaticoduodenal complex, and small and large intestine). Preoperative mean pulmonary artery pressure was <30 mm Hg with a pulmonary vascular resistance of <300 dynes^.s/cm⁵ on oral sildenafil and intravenous epoprostenol. Intraoperatively, management required comprehensive transfusion protocols, a careful balance between correcting blood loss and preventing thrombosis. Intravenous epoprostenol, sildenafil, milrinone, and inhaled nitric oxide were used to reduce elevated mean pulmonary artery pressure and right ventricular strain associated with vascular clamping, reperfusion, and massive fluid shifts. Nitric oxide and epoprostenol use unleashed antiplatelet effects on a patient already susceptible to coagulopathy. A multimodal and multidisciplinary approach continued throughout the surgery and in the postoperative period, which led to a successful outcome.

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.

Visceral arterial embolization prior to multivisceral transplantation in recipient with cirrhosis, extensive portomesenteric thrombosis, and hostile abdomen: Performance and outcome analysis

Multivisceral transplant (MVT) for cirrhosis, and portomesenteric vein thrombosis (PVT), is fraught with life-threatening thrombo-hemorrhagic complications. Embolization of native viscera has been attempted in a handful of cases with mixed results. We carried out a comparative analysis of angiographic, intra-operative, and pathological findings in three recipients of MVT who were deemed exceptionally high hemorrhagic risk and therefore underwent preoperative visceral embolization. All recipients were male with cirrhosis, PVT, and a surgical history indicative of diffuse visceral adhesions; status post-liver transplantation (n = 2) and proctocolectomy (n = 1). The first patient had two Amplatzer II embolization plugs placed 2 cm from the origins of celiac and superior mesenteric (SMA) arteries. Distal migration of the celiac plug into gastroduodenal artery (GDA) and ensuing ischemia reperfusion injury, presumably contributed to severe disseminated intravascular coagulation (DIC) and intra-operative mortality. In the other two recipients, distal Gelfoam embolization of the SMA, GDA, and splenic arteries was performed, and although remarkable hemorrhage and coagulopathy occurred, embolization, undoubtedly, facilitated exenteration and improved outcomes. Pathologic examination in these cases confirmed ischemic necrosis of eviscerated bowel. In conclusion, liver-sparing, preoperative distal embolization of native viscera with Gelfoam is beneficial, but entails several pitfalls. It should currently be reserved for MVT recipients who otherwise are at unacceptably high risk.

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.